An alternative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is to give an externalist account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., a result of a reliable process (and perhaps, further conditions as well). This makes it possible for such a view to retain Internalist account of epistemic justification, though the centrality of that concept to epistemology would obviously be seriously diminished.
Such an externalist account of knowledge can accommodate the commonsense conviction that animals, young children, and unsophisticated adults' posse's knowledge, though not the weaker conviction (if such a conviction does exist) that such individuals are epistemically justified in their beliefs. It is, at least, less vulnerable to Internalist counter-examples of the sort discussed, since the intuitions involved there pertain more clearly to justification than to knowledge. What is uncertain is what ultimate philosophical significance the resulting conception of knowledge, for which is accepted or advanced as true or real on the basis of less than conclusive evidence, as can only be assumed to have. In particular, does it have any serious bearing on traditional epistemological problems and on the deepest and most troubling versions of scepticism, which seems in fact to be primarily concerned with justification, and knowledge?`
A rather different use of the terms 'internalism' and 'externalism' have to do with the issue of how the content of beliefs and thoughts is determined: According to an Internalist view of content, the content of such intention states depends only on the non-relational, internal properties of the individual's mind or grain, and not at all on his physical and social environment: While according to an externalist view, content is significantly affected by such external factors and suggests a view that appears of both internal and external elements are standardly classified as an external view.
As with justification and knowledge, the traditional view of content has been strongly Internalist in character. The main argument for externalism derives from the philosophy y of language, more specifically from the various phenomena pertaining to natural kind terms, indexicals, etc. that motivate the views that have come to be known as 'direct reference' theories. Such phenomena seem at least to show that the belief or thought content that can be properly attributed to a person is dependant on facts about his environment, e.g., whether he is on Earth or Twin Earth, what is fact pointing at, the classificatory criterion employed by expects in his social group, etc. - not just on what is going on internally in his mind or brain.
An objection to externalist account of content is that they seem unable to do justice to our ability to know the content of our beliefs or thought 'from the inside', simply by reflection. If content is depending on external factors pertaining to the environment, then knowledge of content should depend on knowledge of these factors - which will not in general be available to the person whose belief or thought is in question.
The adoption of an externalist account of mental content would seem to support an externalist account of justification, apart from all contentful representation is a belief inaccessible to the believer, then both the justifying statuses of other beliefs in relation to that of the same representation are the status of that content, being totally rationalized by further beliefs for which it will be similarly inaccessible. Thus, contravening the Internalist requirement for justification, as an Internalist must insist that there are no justification relations of these sorts, that our internally associable content can also not be warranted or as stated or indicated without the deviated departure from a course or procedure or from a norm or standard in showing no deviation from traditionally held methods of justification exacting by anything else: But such a response appears lame unless it is coupled with an attempt to show that the externalised account of content is mistaken.
Except for alleged cases of thing s that are evident for one just by being true, it has often been thought, anything is known must satisfy certain criteria as well as being true. Except for alleged cases of self-evident truths, it is often thought that anything that is known must satisfy certain criteria or standards. These criteria are general principles that will make a proposition evident or just make accepting it warranted to some degree. Common suggestions for this role include position ‘p’, e.g., that 2 + 2 = 4, ‘p’ is evident or, if ‘p’ coheres wit h the bulk of one’s beliefs, ‘p’ is warranted. These might be criteria whereby putative self-evident truths, e.g., that one clearly and distinctly conceive s ‘p’, ‘transmit’ the status as evident they already have without criteria to other proposition s like ‘p’, or they might be criteria whereby purely non-epistemic considerations, e.g., facts about logical connections or about conception that need not be already evident or warranted, originally ‘create’ p’s epistemic status. If that in turn can be ‘transmitted’ to other propositions, e.g., by deduction or induction, there will be criteria specifying when it is.
Nonetheless, of or relating to tradition a being previously characterized or specified to convey an idea indirectly, as an idea or theory for consideration and being so extreme a design or quality and lean towards an ecocatorial suggestion that implicate an involving responsibility that include: (1) if a proposition ‘p’, e.g., that 2 + 2 = 4, is clearly and distinctly conceived, then ‘p’ is evident, or simply, (2) if we can’t conceive ‘p’ to be false, then ‘p’ is evident: Or, (3) whenever are immediately conscious o f in thought or experience, e.g,, that we seem to see red, is evident. These might be criteria whereby putative self-evident truth s, e.g., that one clearly and distinctly conceives, e.g., that one clearly and distinctly conceives ‘p’, ‘transmit’ the status as evident they already have for one without criteria to other propositions like ‘p’. Alternatively, they might be criteria whereby epistemic status, e.g., p’s being evident, is originally created by purely non-epistemic considerations, e.g., facts about how ‘p’ is conceived which are neither self-evident is already criterial evident.
The result effect, holds that traditional criteria do not seem to make evident propositions about anything beyond our own thoughts, experiences and necessary truths, to which deductive or inductive criteria ma y be applied. Moreover, arguably, inductive criteria, including criteria warranting the best explanation of data, never make things evident or warrant their acceptance enough to count as knowledge.
Contemporary epistemologists suggest that traditional criteria may need alteration in three ways. Additional evidence may subject even our most basic judgements to rational correction, though they count as evident on the basis of our criteria. Warrant may be transmitted other than through deductive and inductive relations between propositions. Transmission criteria might not simply ‘pass’ evidence on linearly from a foundation of highly evident ‘premisses’ to ‘conclusions’ that are never more evident.
A group of statements, some of which purportedly provide support for another. The statements which purportedly provide the support are the premisses while the statement purportedly support is the conclusion. Arguments are typically divided into two categories depending on the degree of support they purportedly provide. Deductive arguments purportedly provide conclusive support for their conclusions while inductively supports the purported provision that inductive arguments purportedly provided only arguments purportedly in the providing probably of support. Some, but not all, arguments succeed in providing support for their conclusions. Successful deductive arguments are valid while successful inductive arguments are valid while successful inductive arguments are strong. An argument is valid just in case if all its premisses are true its conclusion is schematically doubtlessly true. Deductive logic provides methods for ascertaining whether or not an argument is valid whereas, inductive logic provides methods for ascertaining the degree of support the premisses of an argument confer on its conclusion.
The word modern in philosophy originally meant "new," distinguishing a new historic era both from antiquity and from the intervening Middle Ages. Many things had occurred in the intellectual, religious, political, and social life of Europe to justify the belief of 16th- and 17th-century thinkers in the genuinely new character of their times. The explorations of the world; the Protestant Reformation, with its emphasis on individual faith; the rise of commercial urban society; and the dramatic appearance during the Renaissance of new ideas in all areas of culture stimulated the development of a new philosophical world-view.
The medieval view of the world as a hierarchical order of beings created and governed by God was supplanted by the mechanistic picture of the world as a vast machine, the parts of which move in accordance with strict physical laws, without purpose or will. In this view of the universe, known as Mechanism, science took precedence over spirituality, and the surrounding physical world that we experience and observe received as much, if not more, attention than the world to come. The aim of human life was no longer conceived as preparation for salvation in the next world, but rather as the satisfaction of people’s natural desires. Political institutions and ethical principles ceased to be regarded as reflections of divine command and came to be seen as practical devices created by humans.
The human mind itself seemed an inexhaustible reality, on a par with the physical reality of matter. Modern philosophers had the task of defining more clearly the essence of mind and of matter, and of reasoning about the relation between the two. Individuals ought to see for themselves, they believed, and study the "book of Nature," and in every case search for the truth with their own reason.
Since the 15th century modern philosophy has been marked by a continuing interaction between systems of thought based on a mechanistic, materialistic interpretation of the universe and those founded on a belief in human thought as the only ultimate reality. This interaction has reflected the increasing effect of scientific discovery and political change on philosophical speculation.
This painting from the 19th century depicts Italian scientist Galileo at the Vatican in Rome in the 17th century. Galileo was forced to stand trial for his belief in Copernicanism, or the idea that Earth moves around the Sun. The Roman Catholic Church forced Galileo to publicly denounce Copernicanism and spend the rest of his life under house arrest.
In the new philosophical climate, experience and reason became the sole standards of truth. The first great spokesperson for the new philosophy was the English philosopher and statesman Francis Bacon, who denounced reliance on authority and verbal argument and criticized Aristotelian logic as useless for the discovery of new laws. Bacon called for a new scientific method based on reasoned generalization from careful observation and experiment. He was the first to formulate rules for this new method of drawing conclusions, now known as inductive inference.
English philosopher and statesman Sir Francis Bacon’s philosophical treatise, Novum Organum (1620), is regarded as an important contribution to scientific methodology. In this work Bacon advanced the necessity of experimentation and accurate observation. Writing in aphorisms (concise statements of principle), Bacon outlined four types of false notions or methods that impede the ability to study nature impartially. He labelled these notions the Idols of the Tribe, the Idols of the Cave, the Idols of the Market-place, and the Idols of the Theatre. Novum Organum greatly influenced the later empiricists, including English philosopher John Locke.
The work of Italian physicist and astronomer Galileo was of even greater importance in the development of a new world-view. Galileo brought attention to the importance of applying mathematics to the formulation of scientific laws. This he accomplished by creating the science of mechanics, which applied the principles of geometry to the motions of bodies. The success of mechanics in discovering reliable and useful laws of nature suggested to Galileo and to later scientists that all nature is designed in accordance with mechanical laws.
The struggle between the Roman Catholic Church and 17th-century Italian physicist and astronomer Galileo has become symbolic of the clash between authority and intellectual freedom, but Galileo himself did not foresee any conflict. Using one of the first telescopes, Galileo found evidence to support the Copernican theory that the Earth and the other planets revolved around the Sun. Galileo believed that his scientific findings fell far outside the theological realm. Author Stillman Drake explores Galileo’s shock and disbelief as his disagreement with the church escalated.
These great changes of the 15th and 16th centuries brought about two intellectual crises that profoundly affected Western civilization. First, the decline of Aristotelian science called into question the methods and foundations of the sciences. This decline came about for a number of reasons including the inability of Aristotelian principles to explain new observations in astronomy. Second, new attitudes toward religion undermined religious authority and gave agnostic and atheistic ideas a chance to be heard.
French philosopher and mathematician René Descartes (1596-1650) is sometimes called the father of modern philosophy. In 1649 Descartes was invited by Queen Christina of Sweden to Stockholm to instruct the queen in philosophy. Although treated well by the queen, he was unaccustomed to the cold of Swedish winters and died of pneumonia the following year.
During the 17th century French mathematician, physicist, and philosopher René Descartes attempted to resolve both crises. He followed Bacon and Galileo in criticizing existing methods and beliefs, but whereas Bacon had argued for an inductive method based on observed facts, Descartes made mathematics the model for all science. Descartes championed the truth contained in the "clear and distinct ideas" of reason itself. The advance toward knowledge was from one such truth to another, as in mathematical reasoning. Descartes believed that by following his rationalist method, one could establish first principles (fundamental underlying truths) for all knowledge—about man, the world, and even God.
The 17th century French scientist and mathematician René Descartes was also one of the most influential thinkers in Western philosophy. Descartes stressed the importance of skepticism in thought and proposed the idea that existence had a dual nature: one physical, the other mental. The latter concept, known as Cartesian dualism, continues to engage philosophers today. This passage from Discourse on Method (first published in his Philosophical Essays in 1637) contains a summary of his thesis, which includes the celebrated phrase "I think, therefore I am."
Descartes resolved to reconstruct all human knowledge on an absolutely certain foundation by refusing to accept any belief, even the belief in his own existence, until he could prove it to be necessarily true. In his so-called dream argument, he argued that our inability to prove with certainty when we are awake and when we are dreaming makes most of our knowledge uncertain. Ultimately he concluded that the first thing of whose existence one can be certain are oneself as a thinking being. This conclusion forms the basis of his well-known argument, "Cogito, ergo sum" ("I think, therefore I am"). He also argued that, in pure thought, one has a clear conception of God and can demonstrate that God exists. Descartes argued that secure knowledge of the reality of God allowed him to have his earlier doubts about knowledge and science.
French thinker René Descartes applied rigorous scientific methods of deduction to his exploration of philosophical questions. Descartes is probably best known for his pioneering work in philosophical skepticism. Author Tom Sorell examines the concepts behind Descartes’s work Meditationes de Prima Philosophia (1641; Meditations on First Philosophy), focussing on its unconventional use of logic and the reactions it aroused.
Despite his mechanistic outlook, Descartes accepted the traditional religious doctrine of the immortality of the soul and maintained that mind and body are two distinct substances, thus exempting mind from the mechanistic laws of nature and providing for freedom of the will. His fundamental separation of mind and body, known as dualism, raised the problem of explaining how two such different substances as mind and body can affect each other, a problem he was unable to solve since which has remained a concern of philosophy ever. Descartes’s thought launched an era of speculation in metaphysics as philosophers made a determined effort to overcome dualism -the belief in the irreconcilable difference between mind and matter - and obtain unity. The separation of mind and matter is also known as Cartesian dualism after Descartes.
The 17th–century English philosopher Thomas Hobbes, in his effort to attain unity, asserted that matter is the only real substance. He constructed a comprehensive system of metaphysics that provided a solution to the mind-body problem by reducing mind to the internal motions of the body. He also argued that there is no contradiction between human freedom and causal determinism—the view that every act is determined by a prior cause. Both, according to Hobbes, work in accordance with the mechanical laws that govern the universe.
Seventeenth-century English philosopher Thomas Hobbes’s view of human nature is often characterized as deeply pessimistic. In the famous phrase from Leviathan (1651), Hobbes’s best–known work, "the life of man is nasty, brutish, and short." This excerpt from a study of Hobbes’s work by author Richard Tuck makes it clear, however, that Hobbes developed his theory of human morality and social relations from the humanist tradition prevalent among intellectuals of his time.
In his ethical theory Hobbes derived the rules of human behaviour from the law of self-preservation and justified egoistic action as the natural human tendency. In his political theory he maintained that government and social justice are artificial creations based on social contract (voluntary agreement between people and their government) and maintained by force. In his most famous work, Leviathan (1651), Hobbes justified political authority on the basis that self-interested people who existed in a terrifying "state of nature" - that is, without a ruler - would seek to protect themselves by forming a political commonwealth that had rules and regulations. He concluded that absolute monarchy is the most effective means of preserving peace.
A member of the rationalist school of philosophy, Baruch Spinoza pursued knowledge through deductive reasoning rather than induction from sensory experience. Spinoza applied the theoretical method of mathematics to other realms of inquiry. Following the format of Euclid’s Elements, Spinoza’s Ethics organized morality and religion into definitions, axioms, and postulates.
Whereas Hobbes tried to oppose Cartesian dualism by reducing mind to matter, the 17th-century Dutch philosopher Baruch Spinoza attempted to reduce matter to divine spiritual substance. He constructed a remarkably precise and rigorous system of philosophy that offered new solutions to the mind-body problem and to the conflict between religion and science. Like Descartes, Spinoza maintained that the entire structure of nature can be deduced from a few basic definitions and axioms, on the model of Euclidean geometry. However, Spinoza believed that Descartes’s theory of two substances created an insoluble problem of the way in which mind and bodies interact. He concluded that the ultimate substance is God and that God, substance, and nature are identical. Thus he supported the pantheistic view that all things are aspects or modes of God.
Dutch philosopher Baruch Spinoza is regarded as the foremost Western proponent of pantheism, the belief that God and nature are one and the same. This idea is the central thesis of Spinoza’s most famous and influential work, the 1674 Ethica Ordine Geometrico Demonstrata (Ethics Demonstrated with Geometrical Order). Author Roger Scruton examines Spinoza’s assertion that God is the "substance" of everything.
Spinoza’s solution to the mind-body problem explained the apparent interaction of mind and body by regarding them as two forms of the same substance, which exactly parallel each other, thus seeming to affect each other but not really doing so. Spinoza’s ethics, like the ethics of Hobbes, was based on materialistic psychology according to which individuals are motivated only by self-interest. But in contrast with Hobbes, Spinoza concluded that rational self-interest coincides with the interest of others.
English philosopher John Locke explained his theory of empiricism, a philosophical doctrine holding that all knowledge is based on experience, in An Essay Concerning Human Understanding (1690). Locke believed the human mind to be a blank slate at birth that gathered all its information from its surroundings - starting with simple ideas and combining these simple ideas into more complex ones. His theory greatly influenced education in Great Britain and the United States. Locke believed that education should begin in early childhood and should proceed gradually as the child learns increasingly complex ideas.
English philosopher John Locke responded to the challenge of Cartesian dualism by supporting a commonsense view that the corporeal (bodily or material) and the spiritual are simply two parts of nature that remain always present in human experience. He made no attempt rigorously to define these parts of nature or to construct a detailed system of metaphysics that attempted to explain them; Locke believed that such philosophical aims were impossible to carry out and thus pointless. Against the rationalism of Descartes and Spinoza, who believed in the ability to achieve knowledge through reasoning and logical deduction, Locke continued the empiricist tradition begun by Bacon and embraced by Hobbes. The empiricists believed that knowledge came from observation and sense perceptions rather than from reason alone.
In 1690 Locke gave empiricism a systematic framework with the publication of his Essay Concerning Human Understanding. Of particular importance was Locke’s redirection of philosophy away from the study of the physical world and toward the study of the human mind. In so doing he made epistemology, the study of the nature of knowledge, the principal concern of philosophy in the 17th and 18th century. In his own theory of the mind Locke attempted to reduce all ideas to simple elements of experience, but he distinguished sensation and reflection as sources of experience, sensation providing the material for knowledge of the external world, and reflection the material for knowledge of the mind.
Locke greatly influenced the skepticism of later British thinkers, such as George Berkeley and David Hume, by recognizing the vagueness of the concepts of metaphysics and by pointing out that inferences about the world outside the mind cannot be proved with certainty. His ethical and political writings had an equally great influence on subsequent thought. During the late 18th century the founders of the modern school of utilitarianism, which makes happiness for the largest possible number of people the standard of right and wrong, drew heavily on the writings of Locke. His defence of constitutional government, religious tolerance, and natural human rights influenced the development of liberal thought during the late 18th century in France and the United States as well as in Great Britain.
Efforts to resolve the dualism of mind and matter, a problem first raised by Descartes, continued to engage philosophers during the 17th and 18th centuries. The division between science and religious belief also occupied them. There, the aim was to preserve the essentials of faith in God while at the same time defending the right to think freely. One view called Deism saw God as the cause of the great mechanism of the world, a view more in harmony with science than with traditional religion. Natural science at this time was striding ahead, relying on sense perception as well as reason, and thereby discovering the universal laws of nature and physics. Such empirical (observation-based) knowledge appeared to be more certain and valuable than philosophical knowledge based upon reason alone.
After Locke philosophers became more sceptical about achieving knowledge that they could be certain was true. Some thinkers who despaired of finding a resolution to dualism embraced skepticism, the doctrine that true knowledge, other than what we experience through the senses, are impossible. Others turned to increasingly radical theories of being and knowledge. Among them was German philosopher Immanuel Kant, probably the most influential of all because he set Western philosophy on a new path that it still follows today. Kant’s view that knowledge of the world is dependent upon certain innate categories or ideas in the human mind is known as idealism.
Nevertheless, finding to a theory that magnifies the role of decisions, or free selection from among equally possible alternatives, in order to show that what appears to be objective or fixed by nature is in fact an artefact of human convention, similar to conventions of etiquette, or grammar, or law. Thus one might suppose that moral rules owe more to social convention than to anything imposed from outside, or hat supposedly inexorable necessities are in fact the shadow of our linguistic conventions. The disadvantage of conventionalism is that it must show that alternative, equally workable conventions could have been adopted, and it is often easy to believe that, for example, if we hold that some ethical norm such as respect for promises or property is conventional, we ought to be able to show that human needs would have been equally well satisfied by a system involving a different norm, and this may be hard to establish.
A convention also suggested by Paul Grice (1913-88) directing participants in conversation to pay heed to an accepted purpose or direction of the exchange. Contributions made without paying this attention are liable to be rejected for other reasons than straightforward falsity: Something true but unhelpful or inappropriate may meet with puzzlement or rejection. We can thus never infer fro the fact that it would be inappropriate to say something in some circumstance that what would be aid, were we to say it, would be false. This inference was frequently and in ordinary language philosophy, it being argued, for example, that since we do not normally say ‘there sees to be a barn there’ when there is unmistakably a barn there, it is false that on such occasions there seems to be a barn there.
There are two main views on the nature of theories. According to the ‘received view’ theories are partially interpreted axiomatic systems, according to the semantic view, a theory is a collection of models (Suppe, 1974). However, a natural language comes ready interpreted, and the semantic problem is no that of the specification but of understanding the relationship between terms of various categories (names, descriptions, predicates, adverbs . . .) and their meanings. An influential proposal is that this relationship is best understood by attempting to provide a ‘truth definition’ for the language, which will involve giving terms and structure of different kinds have on the truth-condition of sentences containing them.
The axiomatic method . . . as, . . . a proposition lid down as one from which we may begin, an assertion that we have taken as fundamental, at least for the branch of enquiry in hand. The axiomatic method is that of defining as a set of such propositions, and the ‘proof procedures’ or finding of how a proof ever gets started. Suppose I have as premises (1) p and (2) p q. Can I infer q? Only, it seems, if I am sure of, (3) (p & p q) q. Can I then infer q? Only, it seems, if I am sure that (4) (p & p q) q) q. For each new axiom (N) I need a further axiom (N + 1) telling me that the set so far implies q, and the regress never stops. The usual solution is to treat a system as containing not only axioms, but also rules of reference, allowing movement fro the axiom. The rule ‘modus ponens’ allow us to pass from the first two premises to q. Charles Dodgson Lutwidge (1832-98) better known as Lewis Carroll’s puzzle shows that it is essential to distinguish two theoretical categories, although there may be choice about which to put in which category.
This type of theory (axiomatic) usually emerges as a body of (supposes) truths that are not nearly organized, making the theory difficult to survey or study a whole. The axiomatic method is an idea for organizing a theory (Hilbert 1970): one tries to select from among the supposed truths a small number from which all others can be seen to be deductively inferable. This makes the theory rather more tractable since, in a sense, all the truths are contained in those few. In a theory so organized, the few truths from which all others are deductively inferred are called axioms. In that, just as algebraic and differential equations, which were used to study mathematical and physical processes, could they be made mathematical objects, so axiomatic theories, like algebraic and differential equations, which are means of representing physical processes and mathematical structures, could be made objects of mathematical investigation.
In the traditional (as in Leibniz, 1704), many philosophers had the conviction that all truths, or all truths about a particular domain, followed from a few principles. These principles were taken to be either metaphysically prior or epistemologically prior or in the fist sense, they were taken to be entities of such a nature that what exists is ‘caused’ by them. When the principles were taken as epistemologically prior, that is, as axioms, they were taken to be epistemologically privileged either, e.g., self-evident, not needing to be demonstrated or (again, inclusive ‘or’) to be such that all truths do follow from them (by deductive inferences). Gödel (1984) showed that treating axiomatic theories as themselves mathematical objects, that mathematics, and even a small part of mathematics, elementary number theory, could not be axiomatized, that, more precisely, any class of axioms that in such that we could effectively decide, of any proposition, whether or not it was in the class, would be too small to capture all of the truths.
The use of a model to test for the consistency of an axiomatized system is older than modern logic. Descartes’s algebraic interpretation of Euclidean geometry provides a way of showing that if the theory of real numbers is consistent, so is the geometry. Similar mapping had been used by mathematicians in the 19th century for example to show that if Euclidean geometry is consistent, so are various non-Euclidean geometries. Model theory is the general study of this kind of procedure: The study of interpretations of formal system. Proof theory studies relations of deductibility as defined purely syntactically, that is, without reference to the intended interpretation of the calculus. More formally, a deductively valid argument starting from true premises, that yields the conclusion between formulae of a system. But once the notion of an interpretation is in place we can ask whether a formal system meets certain conditions. In particular, can it lead us from sentences that are true under some interpretation to ones that are false under the same interpretation? And if a sentence is true under all interpretations, is it also a theorem of the system? We can define a notion of validity (a formula is valid if it is true in all interpretations) and semantic consequence (a formula, written as:
{A1 . . . An} B
If it is true in all interpretations in which they are true) The central questions for a calculus will be whether all and only its theorems are valid, and whether {A1 . . . An} B, if and only if {A1. . . . An} B. These are the questions of the soundness and completeness of a formal system. For the propositional calculus this turns into the question of whether the proof theory delivers as theorems all and only tautologies. There are many axiomatizations of the propositional calculus that are consistent an complete. Gödel proved in 1929 that first-order predicate calculus is complete: any formula that is true under every interpretation is a theorem of the calculus.
The propositional calculus or logical calculus whose expressions are character representation sentences or propositions, and constants representing operations on those propositions to produce others of higher complexity. The operations include conjunction, disjunction, material implication and negation (although these need not be primitive). Propositional logic was partially anticipated by the Stoics but researched maturity only with the work of Frége, Russell, and Wittgenstein.
The concept introduced by Frége of a function taking a number of names as arguments, and delivering one proposition as the value. The idea is that ‘÷ loves y’ is a propositional function, which yields the proposition ‘John loves Mary’ from those two arguments (in that order). A propositional function is therefore roughly equivalent to a property or relation. In Principia Mathematica, Russell and Whitehead take propositional functions to be the fundamental function, since the theory of descriptions could be taken as showing that other expressions denoting functions are incomplete symbols.
Keeping in mind, the two classical truth-values that a statement, proposition, or sentence can take. It is supposed in classical (two-valued) logic, that each statement has one of these values, and none has both. A statement is then false if and only if it is not true. The basis of this scheme is that to each statement there corresponds a determinate truth condition, or way the world must be for it to be true, and otherwise false. Statements may be felicitous or infelicitous in other dimensions (polite, misleading, apposite, witty, etc.) but truth is the central normative governing assertion. Considerations of vagueness may introduce greys into a black-and-white scheme. For the issue of whether falsity is the only way of failing to be true.
Formally, it is nonetheless, that any suppressed premise or background framework of thought necessary to make an argument valid, or a position tenable. More formally, a presupposition has been defined as a proposition whose truth is necessary for either the truth or the falsity of another statement. Thus, if ‘p’ presupposes ‘q’, ‘q’ must be true for p to be either true or false. In the theory of knowledge of Robin George Collingwood (1889-1943), any propositions capable of truth or falsity stand on a bed of ‘absolute presuppositions’ which are not properly capable of truth or falsity, since a system of thought will contain no way of approaching such a question. It was suggested by Peter Strawson (1919-), in opposition to Russell’s theory of ‘definite’ descriptions, that ‘there exists a King of France’ is a presupposition of ‘the King of France is bald’, the latter being neither true, nor false, if there is no King of France. It is, however, a little unclear whether the idea is that no statement at all is made in such a case, or whether a statement can made, but fails to present itself as true and opposes of either true is false. The former option preserves classical logic, since we can still say that every statement is either true or false, but the latter does not, since in classical logic the law of ‘bivalence’ holds, and ensures that nothing at all is presupposed for any proposition to be true or false. The introduction of presupposition therefore means that either a third truth-value is found, ‘intermediate’ between truth and falsity, or classical logic is preserved, but it is impossible to tell whether a particular sentence expresses a proposition that is a candidate for truth ad falsity, without knowing more than the formation rules of the language. Each suggestion carries costs, and there is some consensus that at least where definite descriptions are involved, examples like the one given are equally well handed by regarding the overall sentence false when the existence claim fails.
A proposition may be true or false it is said to take the truth-value true, and if the latter the truth-value false. The idea behind the term is the analogy between assigning a propositional variable one or other of these values, as a formula of the propositional calculus, and assigning an object as the value of many other variable. Logics with intermediate values are called many-valued logics. Then, a truth-function of a number of propositions or sentences is a function of them that has a definite truth-value, depends only on the truth-values of the constituents. Thus (p & q) is a combination whose truth-value is true when ‘p’ is true and ‘q’ is true, and false otherwise, ¬ p is a truth-function of ‘p’, false when ‘p’ is true and true when ‘p’ is false. The way in which the value of the whole is determined by the combinations of values of constituents is presented in a truth table.
In whatever manner, truths of fact cannot be reduced to any identity and our only way of knowing them is a posteriori, by reference to the facts of the empirical world.
A proposition is knowable a priori if it can be known without experience of the specific course of events in the actual world. It may, however, be allowed that some experience is required to acquire the concepts involved in an a priori proposition. Some thing is knowable only a posteriori if it can be known a priori. The distinction given one of the fundamental problem areas of epistemology. The category of a priori propositions is highly controversial, since it is not clear how pure thought, unaided by experience, can give rise to any knowledge at all, and it has always been a concern of empiricism to deny that it can. The two great areas in which it seems to be so are logic and mathematics, so empiricists have commonly tried to show either that these are not areas of real, substantive knowledge, or that in spite of appearances their knowledge that we have in these areas is actually dependent on experience. The former line tries to show sense trivial or analytic, or matters of notation conventions of language. The latter approach is particularly y associated with Quine, who denies any significant slit between propositions traditionally thought of as a priori, and other deeply entrenched beliefs that occur in our overall view of the world.
Another contested category is that of a priori concepts, supposed to be concepts that cannot be ‘derived’ from experience, but which are presupposed in any mode of thought about the world, time, substance, causation, number, and self are candidates. The need for such concept s, and the nature of the substantive a prior knowledge to which they give rise, is the central concern of Kant ‘s Critique of Pure Reason.
Likewise, since their denial does not involve a contradiction, there is merely contingent: Their could have been in other ways a hold of the actual world, but not every possible one. Some examples are ‘Caesar crossed the Rubicon’ and ‘Leibniz was born in Leipzig’, as well as propositions expressing correct scientific generalizations. In Leibniz’s view truths of fact rest on the principle of sufficient reason, which is a reason why it is so. This reason is that the actual world (by which he means the total collection of things past, present and future) is better than any other possible world and therefore created by God. The foundation of his thought is the conviction that to each individual there corresponds a complete notion, knowable only to God, from which is deducible all the properties possessed by the individual at each moment in its history. It is contingent that God actualizes te individual that meets such a concept, but his doing so is explicable by the principle of ‘sufficient reason’, whereby God had to actualize just that possibility in order for this to be the best of all possible worlds. This thesis is subsequently lampooned by Voltaire (1694-1778), in whom of which was prepared to take refuge in ignorance, as the nature of the soul, or the way to reconcile evil with divine providence.
In defending the principle of sufficient reason sometimes described as the principle that nothing can be so without there being a reason why it is so. But the reason has to be of a particularly potent kind: eventually it has to ground contingent facts in necessities, and in particular in the reason an omnipotent and perfect being would have for actualizing one possibility than another. Among the consequences of the principle is Leibniz’s relational doctrine of space, since if space were an infinite box there could be no reason for the world to be at one point in rather than another, and God placing it at any point violate the principle. In Abelard’s (1079-1142), as in Leibniz, the principle eventually forces te recognition that the actual world is the best of all possibilities, since anything else would be inconsistent with the creative power that actualizes possibilities.
If truth consists in concept containment, then it seems that all truths are analytic and hence necessary; and if they are all necessary, surely they are all truths of reason. In that not every truth can be reduced to an identity in a finite number of steps; in some instances revealing the connection between subject and predicate concepts would require an infinite analysis, while this may entail that we cannot prove such proposition as a prior, it does not appear to show that proposition could have been false. Intuitively, it seems a better ground for supposing that it is a necessary truth of a special sort. A related question arises from the idea that truths of fact depend on God’s decision to create the best world: If it is part of the concept of this world that it is best, how could its existence be other than necessary? An accountable and responsively answered explanation would be so, that any relational question that brakes the norm lay eyes on its existence in the manner other than hypothetical necessities, i.e., it follows from God’s decision to create the world, but God had the power to create this world, but God is necessary, so how could he have decided to do anything else? Leibniz says much more about these matters, but it is not clear whether he offers any satisfactory solutions.
The view that the terms in which we think of some area are sufficiently infected with error for it to be better to abandon them than to continue to try to give coherent theories of their use. Eliminativism should be distinguished from scepticism that claims that we cannot know the truth about some area; eliminativism claims rather that there are no truth there to be known, in the terms that we currently think. An eliminativist about theology simply counsels abandoning the terms or discourse of theology, and that will include abandoning worries about the extent of theological knowledge.
Eliminativists in the philosophy of mind counsel abandoning the whole network of terms mind, consciousness, self, Qualia that usher in the problems of mind and body. Sometimes the argument for doing this is that we should wait for a supposed future understanding of ourselves, based on cognitive science and better than any our current mental descriptions provide, sometimes it is supposed that physicalism shows that no mental description of ourselves could possibly be true.
Greek scepticism centred on the value of enquiry and questioning, scepticism is now the denial that knowledge or even rational belief is possible, either about some specific subject-matter, e.g., ethics, o r in any atra whatsoever. Classically, scepticism springs from the observation that the best methods in some area seem to fall short of giving us contact with the truth, e.g., there is a gulf between appearance and reality, and in frequency cites the conflicting judgements that our methods deliver, with the result that questions of truth become undecidable.
Sceptical tendencies emerged in the 14th-century writings of Nicholas of Autrecourt. His criticisms of any certainty beyond the immediate deliverance of the senses and basic logic, and in particular of any knowledge of either intellectual or material substances, anticipate the later scepticism of Balye and Hume. The; later distinguishes between Pyrrhonistic and excessive scepticism, which he regarded as unlivable, and the more mitigated scepticism that accepts every day or commonsense beliefs (not as the delivery of reason, but as due more to custom and habit), but is duly wary of the power of reason to give us much more. Mitigated scepticism is thus closer to the attitude fostered by ancient scepticism from Pyrrho through to Sexus Empiricus. Although the phrase ‘Cartesian scepticism’ is sometimes used, Descartes himself was not a sceptic, but in the method of doubt, uses a sceptical scenario in order to begin the process of finding a secure mark of knowledge. Descartes himself trusts a category of ‘clear and distinct’ ideas, not far removed from the phantasia kataleptiké of the Stoics.
Scepticism should not be confused with relativism, which is a doctrine about the nature of truth, and may be motivated by trying to avoid scepticism. Nor is it identical with eliminativism, which counsels abandoning an area of thought altogether, not because we cannot know the truth, but because there are no truths capable of being framed in the terms we use.
Descartes’s theory of knowledge starts with the quest for certainty, for an indubitable starting-point or foundation on the basis alone of which progress is possible. This is eventually found in the celebrated ‘Cogito ergo sum’: I think therefore I am. By locating the point of certainty in my own awareness of my own self, Descartes gives a first-person twist to the theory of knowledge that dominated them following centuries in spite of various counter-attacks on behalf of social and public starting-points. The metaphysical associated with this priority are the famous Cartesian dualism, or separation of mind and matter into two different but interacting substances, Descartes rigorously and rightly see that it takes divine dispensation to certify any relationship between the two realms thus divided, and to prove the reliability of the senses invokes a ‘clear and distinct perception’ of highly dubious proofs of the existence of a benevolent deity. This has not met general acceptance: as Hume drily puts it, ‘to have recourse to the veracity of the supreme Being, in order to prove the veracity of our senses, is surely making a very unexpected circuit’.
In his own time Descartes’s conception of the entirely separate substance of the mind was recognized to give rise to insoluble problems of the nature of the causal connection between the two. It also gives rise to the problem, insoluble in its own terms, of other minds. Descartes’s notorious denial that non-human animals are conscious is a stark illustration of the problem. In his conception of matter Descartes also gives preference to rational cogitation over anything derived from the senses. Since we can conceive of the matter of a ball of wax surviving changes to its sensible qualities, matter is not an empirical concept, but eventually an entirely geometrical one, with extension and motion as its only physical nature. Descartes’s thought, as reflected in Leibniz, that the qualities of sense experience have no resemblance to qualities of things, so that knowledge of the external world is essentially knowledge of structure rather than of filling. On this basis Descartes erects a remarkable physics. Since matter is in effect the same as extension there can be no empty space or ‘void’, since there is no empty space motion is not a question of occupying previously empty space, but is to be thought of in terms of vortices (like the motion of a liquid).
Although the structure of Descartes’s epistemology, theories of mind, and theory of matter have been rejected many times, their relentless exposure of the hardest issues, their exemplary clarity, and even their initial plausibility, all contrives to make him the central point of reference for modern philosophy.
The self conceived as Descartes presents it in the first two Meditations: aware only of its own thoughts, and capable of disembodied existence, neither situated in a space nor surrounded by others. This is the pure self of ‘I-ness’ that we are tempted to imagine as a simple unique thing that make up our essential identity. Descartes’s view that he could keep hold of this nugget while doubting everything else is criticized by Lichtenberg and Kant, and most subsequent philosophers of mind.
Descartes holds that we do not have any knowledge of any empirical proposition about anything beyond the contents of our own minds. The reason, roughly put, is that there is a legitimate doubt about all such propositions because there is no way to deny justifiably that our senses are being stimulated by some cause (an evil spirit, for example) which is radically different from the objects that we normally think affect our senses.
He also points out, that the senses (sight, hearing, touch, etc., are often unreliable, and ‘it is prudent never to trust entirely those who have deceived us even once’, he cited such instances as the straight stick that looks ben t in water, and the square tower that look round from a distance. This argument of illusion, has not, on the whole, impressed commentators, and some of Descartes’ contemporaries pointing out that since such errors come to light as a result of further sensory information, it cannot be right to cast wholesale doubt on the evidence of the senses. But Descartes regarded the argument from illusion as only the first stage in softening up process which would ‘lead the mind away from the senses’. He admits that there are some cases of sense-base belief about which doubt would be insane, e.g., the belief that I am sitting here by the fire, wearing a winter dressing gown’.
Descartes was to realize that there was nothing in this view of nature that could explain or provide a foundation for the mental, or from direct experience as distinctly human. In a mechanistic universe, he said, there is no privileged place or function for mind, and the separation between mind and matter is absolute. Descartes was also convinced, that the immaterial essences that gave form and structure to this universe were coded in geometrical and mathematical ideas, and this insight led him to invent algebraic geometry.
A scientific understanding of these ideas could be derived, said Descartes, with the aid of precise deduction, and he also claimed that the contours of physical reality could be laid out in three-dimensional coordinates. Following the publication of Newton’s Principia Mathematica in 1687, reductionism and mathematical modelling became the most powerful tools of modern science. And the dream that the entire physical world could be known and mastered through the extension and refinement of mathematical theory became the central feature and guiding principle of scientific knowledge.
Having to its recourse of knowledge, its cental questions include the origin of knowledge, the place of experience in generating knowledge, and the place of reason in doing so, the relationship between knowledge and certainty, and between knowledge and the impossibility of error, the possibility of universal scepticism, and the changing forms of knowledge that arise from new conceptualizations of the world. All of these issues link with other central concerns of philosophy, such as the nature of truth and the natures of experience and meaning.
Foundationalism was associated with the ancient Stoics, and in the modern era with Descartes (1596-1650). Who discovered his foundations in the ‘clear and distinct’ ideas of reason? Its main opponent is Coherentism, or the view that a body of propositions mas be known without a foundation in certainty, but by their interlocking strength, than as a crossword puzzle may be known to have been solved correctly even if each answer, taken individually, admits of uncertainty. Difficulties at this point led the logical passivists to abandon the notion of an epistemological foundation altogether, and to flirt with the coherence theory of truth. It is widely accepted that trying to make the connection between thought and experience through basic sentences depends on an untenable ‘myth of the given’.
Still in spite of these concerns, the problem, least of mention, is of defining knowledge in terms of true beliefs plus some favoured relations between the believer and the facts that began with Plato’s view in the "Theaetetus," that knowledge is true belief, and some logos. Due of its nonsynthetic epistemology, the enterprising of studying the actual formation of knowledge by human beings, without aspiring to certify those processes as rational, or its proof against ‘scepticism’ or even apt to yield the truth. Natural epistemology would therefore blend into the psychology of learning and the study of episodes in the history of science. The scope for ‘external’ or philosophical reflection of the kind that might result in scepticism or its refutation is markedly diminished. Despite the fact that the terms of modernity are so distinguished as exponents of the approach include Aristotle, Hume, and J. S. Mills.
The task of the philosopher of a discipline would then be to reveal the correct method and to unmask counterfeits. Although this belief lay behind much positivist philosophy of science, few philosophers now subscribe to it. It places too well a confidence in the possibility of a purely previous ‘first philosophy’, or viewpoint beyond that of the work one’s way of practitioners, from which their best efforts can be measured as good or bad. These standpoints now seem that too many philosophers to be a fanciefancy, that the more modest of tasks that are actually adopted at various historical stages of investigation into different areas with the aim not so much of criticizing but more of systematization, in the presuppositions of a particular field at a particular tie. There is still a role for local methodological disputes within the community investigators of some phenomenon, with one approach charging that another is unsound or unscientific, but logic and philosophy will not, on the modern view, provide an independent arsenal of weapons for such battles, which indeed often come to seem more like political bids for ascendancy within a discipline.
This is an approach to the theory of knowledge that sees an important connection between the growth of knowledge and biological evolution. An evolutionary epistemologist claims that the development of human knowledge processed through some natural selection process, the best example of which is Darwin’s theory of biological natural selection. There is a widespread misconception that evolution proceeds according to some plan or direct, but it has neither, and the role of chance ensures that its future course will be unpredictable. Random variations in individual organisms create tiny differences in their Darwinian fitness. Some individuals have more offsprings than others, and the characteristics that increased their fitness thereby become more prevalent in future generations. Once upon a time, at least a mutation occurred in a human population in tropical Africa that changed the haemoglobin molecule in a way that provided resistance to malaria. This enormous advantage caused the new gene to spread, with the unfortunate consequence that sickle-cell anaemia came to exist.
Chance can influence the outcome at each stage: First, in the creation of genetic mutation, second, in wether the bearer lives long enough to show its effects, thirdly, in chance events that influence the individual’s actual reproductive success, and fourth, in whether a gene even if favoured in one generation, is, happenstance, eliminated in the next, and finally in the many unpredictable environmental changes that will undoubtedly occur in the history of any group of organisms. As Harvard biologist Stephen Jay Gould has so vividly expressed that process over again, the outcome would surely be different. Not only might there not be humans, there might not even be anything like mammals.
We will often emphasis the elegance of traits shaped by natural selection, but the common idea that nature creates perfection needs to be analysed carefully. The extent to which evolution achieves perfection depends on exactly what you mean. If you mean "Does natural selections always take the best path for the long-term welfare of a species?" The answer is no. That would require adaption by group selection, and this is, unlikely. If you mean "Does natural selection creates every adaption that would be valuable?" The answer again, is no. For instance, some kinds of South American monkeys can grasp branches with their tails. The trick would surely also be useful to some African species, but, simply because of bad luck, none have it. Some combination of circumstances started some ancestral South American monkeys using their tails in ways that ultimately led to an ability to grab onto branches, while no such development took place in Africa. Mere usefulness of a trait does not necessitate a means in that what will understandably endure phylogenesis or evolution.
This is an approach to the theory of knowledge that sees an important connection between the growth of knowledge and biological evolution. An evolutionary epistemologist claims that the development of human knowledge proceeds through some natural selection process, the best example of which is Darwin’s theory of biological natural selection. The three major components of the model of natural selection are variation selection and retention. According to Darwin’s theory of natural selection, variations are not pre-designed to do certain functions. Rather, these variations that do useful functions are selected. While those that do not employ of some coordinates in that are regainfully purposed are also, not to any of a selection, as duly influenced of such a selection, that may have responsibilities for the visual aspects of variations in the intentionality for which it occurs. In the modern theory of evolution, genetic mutations provide the blind variations: Blind in the sense that variations are not influenced by the effects they would have-the likelihood of a mutation is not correlated with the benefits or liabilities that mutation would confer on the organism, the environment provides the filter of selection, and reproduction provides the retention. Fatnesses are achieved because those organisms with features that make them less adapted for survival do not survive in connection with other organisms in the environment that have features that are better adapted. Evolutionary epistemology applies this blind variation and selective retention model to the growth of scientific knowledge and to human thought processes overall.
The parallel between biological evolution and conceptual or ‘epistemic’ evolution can be seen as either literal or analogical. The literal version of evolutionary epistemology deeds biological evolution as the main cause of the growth of knowledge. On this view, called the ‘evolution of cognitive mechanic programs’, by Bradie (1986) and the ‘Darwinian approach to epistemology’ by Ruse (1986), that growth of knowledge occurs through blind variation and selective retention because biological natural selection itself is the cause of epistemic variation and selection. The most plausible version of the literal view does not hold that all human beliefs are innate but rather than the mental mechanisms that guide the acquisitions of non-innate beliefs are themselves innately and the result of biological natural selection. Ruse, (1986) demands of a version of literal evolutionary epistemology that he links to sociolology (Rescher, 1990).
On the analogical version of evolutionary epistemology, called the ‘evolution of theory’s program’, by Bradie (1986). The ‘Spenserians approach’ (after the nineteenth century philosopher Herbert Spencer) by Ruse (1986), the development of human knowledge is governed by a process analogous to biological natural selection, rather than by an instance of the mechanism itself. This version of evolutionary epistemology, introduced and elaborated by Donald Campbell (1974) as well as Karl Popper, sees the [partial] fit between theories and the world as explained by a mental process of trial and error known as epistemic natural selection.
Both versions of evolutionary epistemology are usually taken to be types of naturalized epistemology, because both take some empirical facts as a starting point for their epistemological project. The literal version of evolutionary epistemology begins by accepting evolutionary theory and a materialist approach to the mind and, from these, constructs an account of knowledge and its developments. In contrast, the metaphorical version does not require the truth of biological evolution: It simply draws on biological evolution as a source for the model of natural selection. For this version of evolutionary epistemology to be true, the model of natural selection need only apply to the growth of knowledge, not to the origin and development of species. Crudely put, evolutionary epistemology of the analogical sort could still be true even if Creationism is the correct theory of the origin of species.
Although they do not begin by assuming evolutionary theory, most analogical evolutionary epistemologists are naturalized epistemologists as well, their empirical assumptions, least of mention, implicitly come from psychology and cognitive science, not evolutionary theory. Sometimes, however, evolutionary epistemology is characterized in a seemingly non-naturalistic fashion. Campbell (1974) says that ‘if one is expanding knowledge beyond what one knows, one has no choice but to explore without the benefit of wisdom’, i.e., blindly. This, Campbell admits, makes evolutionary epistemology close to being a tautology (and so not naturalistic). Evolutionary epistemology does assert the analytic claim that when expanding one’s knowledge beyond what one knows, one must precessed to something that is already known, but, more interestingly, it also makes the synthetic claim that when expanding one’s knowledge beyond what one knows, one must proceed by blind variation and selective retention. This claim is synthetic because it can be empirically falsified. The central claim of evolutionary epistemology is synthetic, not analytic. If the central contradictory, which they are not. Campbell is right that evolutionary epistemology does have the analytic feature he mentions, but he is wrong to think that this is a distinguishing feature, since any plausible epistemology has the same analytic feature (Skagestad, 1978).
Two extraordinary issues lie to awaken the literature that involves questions about ‘realism’, i.e., What metaphysical commitment does an evolutionary epistemologist have to make? Progress, i.e., according to evolutionary epistemology, does knowledge develop toward a goal? With respect to realism, many evolutionary epistemologists endorse that is called ‘hypothetical realism’, a view that combines a version of epistemological ‘scepticism’ and tentative acceptance of metaphysical realism. With respect to progress, the problem is that biological evolution is not goal-directed, but the growth of human knowledge seems to be. Campbell (1974) worries about the potential dis-analogy here but is willing to bite the stone of conscience and admit that epistemic evolution progress toward a goal (truth) while biologic evolution does not. Many another has argued that evolutionary epistemologists must give up the ‘truth-topic’ sense of progress because a natural selection model is in essence, is non-teleological, as an alternative, following Kuhn (1970), and embraced in the accompaniment with evolutionary epistemology.
Among the most frequent and serious criticisms levelled against evolutionary epistemology is that the analogical version of the view is false because epistemic variation is not blind (Skagestad, 1978, 613-16, and Ruse, 1986, ch.2 (. Stein and Lipton (1990) have argued, however, that this objection fails because, while epistemic variation is not random, its constraints come from heuristics that, for the most part, are selective retention. Further, Stein and Lipton come to the conclusion that heuristics are analogous to biological pre-adaptions, evolutionary pre-biological pre-adaptions, evolutionary cursors, such as a half-wing, a precursor to a wing, which have some function other than the function of their descendable structures: The function of descendable structures, the function of their descendable character embodied to its structural foundations, is that of the guidelines of epistemic variation is, on this view, not the source of disanalogy, but the source of a more articulated account of the analogy.
Many evolutionary epistemologists try to combine the literal and the analogical versions (Bradie, 1986, and Stein and Lipton, 1990), saying that those beliefs and cognitive mechanisms, which are innate results from natural selection of the biological sort and those that are innate results from natural selection of the epistemic sort. This is reasonable as long as the two parts of this hybrid view are kept distinct. An analogical version of evolutionary epistemology with biological variation as its only source of blondeness would be a null theory: This would be the case if all our beliefs are innate or if our non-innate beliefs are not the result of blind variation. An appeal to the legitimate way to produce a hybrid version of evolutionary epistemology since doing so trivializes the theory. For similar reasons, such an appeal will not save an analogical version of evolutionary epistemology from arguments to the effect that epistemic variation is blind (Stein and Lipton, 1990).
Although it is a new approach to theory of knowledge, evolutionary epistemology has attracted much attention, primarily because it represents a serious attempt to flesh out a naturalized epistemology by drawing on several disciplines. In science is relevant to understanding the nature and development of knowledge, then evolutionary theory is among the disciplines worth a look. Insofar as evolutionary epistemology looks there, it is an interesting and potentially fruitful epistemological programme.
What makes a belief justified and what makes a true belief knowledge? Thinking that whether a belief deserves one of these appraisals is natural depends on what caused the depicted branch of knowledge to have the belief. In recent decades a number of epistemologists have pursued this plausible idea with a variety of specific proposals. Some causal theories of knowledge have it that a true belief that ‘p’ is knowledge just in case it has the right causal connection to the fact that ‘p’. Such a criterion can be applied only to cases where the fact that ‘p’ is a sort that can enter into causal relations, as this seems to exclude mathematically and the necessary facts and perhaps any fact expressed by a universal generalization, and proponents of this sort of criterion have usually supposed that it is limited to perceptual representations where knowledge of particular facts about subjects’ environments.
For example, Armstrong (1973), predetermined that a position held by a belief in the form ‘This perceived object is ‘F’ is [non-inferential] knowledge if and only if the belief is a completely reliable sign that the perceived object is ‘F’, that is, the fact that the object is ‘F’ contributed to causing the belief and its doing so depended on properties of the believer such that the laws of nature dictated that, for any subject ‘÷’ and perceived object ‘y’, if ‘÷’ has those properties and believed that ‘y’ is ‘F’, then ‘y’ is ‘F’. (Dretske (1981) offers a rather similar account, in terms of the belief’s being caused by a signal received by the perceiver that carries the information that the object is ‘F’).
Goldman (1986) has proposed an importantly different causal criterion, namely, that a true belief is knowledge if it is produced by a type of process that is ‘globally’ and ‘locally’ reliable. Causing true beliefs is sufficiently high is globally reliable if its propensity. Local reliability has to do with whether the process would have produced a similar but false belief in certain counterfactual situations alternative to the actual situation. This way of marking off true beliefs that are knowledge does not require the fact believed to be causally related to the belief, and so it could in principle apply to knowledge of any kind of truth.
Goldman requires the global reliability of the belief-producing process for the justification of a belief, he requires it also for knowledge because justification is required for knowledge. What he requires for knowledge, but does not require for justification is local reliability. His idea is that a justified true belief is knowledge if the type of process that produced it would not have produced it in any relevant counterfactual situation in which it is false. Its purported theory of relevant alternatives can be viewed as an attempt to provide a more satisfactory response to this tension in our thinking about knowledge. It attempts to characterize knowledge in a way that preserves both our belief that knowledge is an absolute concept and our belief that we have knowledge.
According to the theory, we need to qualify rather than deny the absolute character of knowledge. We should view knowledge as absolute, reactive to certain standards (Dretske, 1981 and Cohen, 1988). That is to say, in order to know a proposition, our evidence need not eliminate all the alternatives to that preposition, rather for ‘us’, that we can know our evidence eliminates al the relevant alternatives, where the set of relevant alternatives (a proper subset of the set of all alternatives) is determined by some standard. Moreover, according to the relevant alternatives view, and the standards determining that of the alternatives is raised by the sceptic are not relevant. If this is correct, then the fact that our evidence cannot eliminate the sceptic’s alternative does not lead to a sceptical result. For knowledge requires only the elimination of the relevant alternatives, so the relevant alternative view preserves in both strands in our thinking about knowledge. Knowledge is an absolute concept, but because the absoluteness is relative to a standard, we can know many things.
The interesting thesis that counts as a causal theory of justification (in the meaning of ‘causal theory’ intended here) is that: A belief is justified in case it was produced by a type of process that is ‘globally’ reliable, that is, its propensity to produce true beliefs-that can be defined (to a good approximation) As the proportion of the beliefs it produces (or would produce) that is true is sufficiently great.
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