Context (World Philosophers and Their Works)
According to Bertrand Russell, the phrase “theory of knowledge” has two meanings. One kind of theory, the lesser, accepts whatever knowledge science presents and seeks to account for it. Russell’s concern is with the wider kind, which embraces all problems of establishing the nature and validity of all knowledge. Confining his attention in this work to empirical knowledge, he undertakes to discover two things: (1) What is meant by “empirical evidence for the truth of a proposition”? (2) What can be inferred from the fact that there sometimes is such evidence?
Russell brings to the problem of a theory of empirical knowledge the full force of its counterpart, logical knowledge, to whose modern development he is a foremost contributor. He attacks the problems of his general task by translating their elements into formal logical symbols so as to achieve a precision lacking in the language in which the problems are usually couched. Yet the book does not consider problems of logic as such, except when they are relevant to epistemology.
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Language (World Philosophers and Their Works)
To talk about epistemological matters, Russell sets up a modern linguistic apparatus. He conceives a hierarchy of languages, at whose base is the object-language, or primary language. Terms in the object-language include subjects and predicates. While ordinary language may provide a beginning, every subject of the object-language should be transformed into a unique proper name, making use of coordinates in the visual field and of measures of time for discriminating the object named. The name will apply to a complex; and sometimes names must be given to complex wholes without knowing what their constituents are. People learn the names of things ostensively, and only of those things they actually perceive while hearing or coining their names. The names are employed as subjects in propositions of the simplest sort, called atomic propositions. Their predicates may be designated relations. Letting R stand for the relation “above,” the proposition “A R B” consists of the relation R and the names A and B, and asserts that A is above B. This is a dyadic relation. Predicates may take any number of terms. The predicate of a single name is a monadic relation: “f (A)” states that a characteristic f is an attribute of A.
The secondary language consists of statements about the primary language (and must include the primary language within...
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Propositions (World Philosophers and Their Works)
The distinctive feature of empirical rather than logical truth is, of course, its basis in percepts, the sense images by which perception is possible. Russell adapts A. J. Ayer’s phrase “basic propositions” to designate those propositions arising as immediately as possible from percepts. A basic proposition “is a proposition which arises on occasion of a perception, which is the evidence for its truth, and it has a form such that no two propositions having this form can be mutually inconsistent if derived from different percepts.” Examples in ordinary language are “I am hot,” “That is red.” Many basic propositions may arise describing a single percept, for people perceive a sensory whole combining the entire fields of vision, touch, and so on; and within this field people identify smaller wholes of sensory complexes—the individual objects of the world. Basic propositions need not be atomic propositions. An important group includes some propositions stating propositional attitudes—”I believe proposition p”—and thus basic propositions may occur in the secondary language as well as in the primary.
Unlike most prior writers, Russell does not affirm that basic propositions are indubitably true. He is quite willing to doubt them, particularly those involving the memory of percepts. However, what distinguishes basic propositions from others is their immediacy, whereas other propositions rest to some degree on inference. The...
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Empirical Knowledge (World Philosophers and Their Works)
A pure empiricism, depending only upon percepts for validation, would be self-refuting. It must contain some general proposition, which cannot be a basic proposition, about the dependence of knowledge upon experience; and the consequence is that such a proposition could not itself be known. Empirical knowledge requires certain additional elements besides basic propositions. These include provisions for making general statements and for stating logical relationships. Empirical knowledge, in other words, needs some epistemological premises as well as factual premises. Modes of inference are also required. These modes include the usual logical operations of deduction. More important in empirical knowledge, however, are nonlogical patterns of inference, namely, reasoning by analogy and by induction. For example, Russell throughout assumes that things perceived cause perceptions, and that perceptions cause propositions. His notion of cause is that it is a convenient device for collecting together propositions of certain percepts; it is something that one can arrive at inductively from appropriate combinations of percepts. Without some such organizing scheme for relating percepts, one would have nothing resembling empirical science. Yet neither causality nor induction is perceived, nor are they validated by logical syntax.
An innovation, no doubt startling to logicians, that Russell finds necessary to epistemology is to supply substantial...
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A Theory of Significance (World Philosophers and Their Works)
Russell is now able to develop a theory of significance. Regarded epistemologically, a proposition has two sides, objective and subjective. The objective side is what it indicates factually. The subjective side is what it expresses about the state of mind of its originator; this is called its significance. What it expresses may be belief, denial, or doubt. These distinctions, not needed in logic, solve many puzzles of epistemology. The points concerning significance are independent of truth or falsity of the proposition; truth and falsity come into the relation of the proposition to what it indicates. A proposition does not necessarily consist of words; it is psychological, of the stuff of belief, not language. However, words may always be found to state the belief that, as a proposition, may underlie the many possible ways of saying it, in one or in various languages. Russell provides a sample language to show that the psychological conditions of significance can be translated into precise syntactical rules.
Logical sentence patterns can start from particular propositions recording percepts and extend one’s thought over material that one has not experienced, and in this way one can expand one’s body of statement. If one knows “Socrates is mortal,” one can think “Something is mortal,” or “Everything is mortal,” and so on. Then further inquiry so as to have new percepts may test whether the new statements should...
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A Theory of Truth (World Philosophers and Their Works)
Among the many possible theories of truth, Russell adheres firmly to a correspondence theory. Truth is defined by events, not percepts, although it becomes known by percepts. Truth is thus a broader concept than knowledge. The truth of a proposition is established by perception of its verifier. The sort of sentence that provides the model for truth is a spontaneous sentence that expresses what it indicates—that is, in which the subjective and the objective content coincide. Such a sentence is “I am hot!” Provided the sentence is stimulated by the immediate circumstances of the moment, there is no reason to doubt it. The verifier of a true sentence is what the sentence indicates; in other words, what makes that sentence true is that I was hot when I said it. Similarly, the verifier of a sentence about the future is the occurrence of what it indicates, and when that occurrence is perceived, the sentence is verified. A false sentence has no verifier, and it indicates nothing. Obviously, some verifiers may never be perceived, and there are some sentences whose truth or falsity is never known. Sentences are true if their verifiers occur, but when verifiers are not perceived, the sentences cannot be said to be known. The presence of an observer, Russell affirms, is no requisite of verifiers occurring.
The verifier of a basic proposition is a single occurrence at a moment of time. As to sentences containing variables, there is (usually)...
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Logical Difficulties (World Philosophers and Their Works)
Certain principles of logic present difficulties in epistemological language when one attempts to apply nonsyntactic criteria of truth. They are the principles of extensionality and atomicity. Loosely, the principle of extensionality allows one to insert any atomic proposition in the place of a given atomic proposition in a sentence in the secondary language. However, this will obviously not do for sentences stating propositional attitudes. “A believes p” should not entitle one to say, by substitution, that A believes any or all propositions whatever. The principle of atomicity in effect requires one to reduce the complex parts of any proposition on a higher language level to their components on the atomic level, then be governed in assessing the truth of the whole by the relationships thus exhibited. Difficulties that these two principles raise in logic were attacked by Ludwig Wittgenstein and other philosophers by distinguishing between the assertion of a proposition and the mere consideration of a proposition. Russell affirmed, however, that the appropriate distinction to be made is between indication and significance.
The principle of extensionality will be found to apply to all occurrences of a proposition within a larger proposition when its indication is what is relevant, but not when only its significance is relevant, as is the case with sentences of propositional attitudes. Russell is less sure whether atomicity...
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Bibliography (World Philosophers and Their Works)
Dejnozka, Jan. Bertrand Russell on Modality and Logical Relevance. Avebury Series on Philosophy. Aldershot: Ashgate, 1999. This work presents a criticism and interpretation of modality and logical relevance in the work of Bertrand Russell. Includes index.
Grayling, A. C. Russell. Past Masters series. Oxford: Oxford University Press, 1996. This work, part of a series on great thinkers, covers the life and accomplishments of Russell. Includes an index.
Irvine, A. D., ed. Bertrand Russell: Critical Assessments. London: Routledge, 1999. This book critically examines the life and work of Russell, including his philosophy.
Landini, Gregory. Russell’s Hidden Substitutional Theory. New York: Oxford University Press, 1998. This work takes a closer look at one of Russell’s logical theories. Includes index.
Monk, Ray. Bertrand Russell: The Spirit of Solitude. London: J. Cape, 1996. This biography of Russell examines the philosopher’s life and works. Includes bibliographical references and index.
Monk, Ray. Bertrand Russell: The Ghost of Madness 1921-1970. London: Jonathon Cape, 2001. Volume 2 of Monk’s thorough biography, covering the troubled mature years of the philosopher.
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