Philosopher Ludwig Wittgenstein had an enormous influence on twentieth-century philosophy even though only one of his works, the famous Tractatus Logico-Philosophicus, was published in his lifetime. Beyond this publication the impact of his thought was mainly conveyed to a small circle of students through his lectures at Cambridge University. Fortunately, many of his ideas have survived in both the dictations that were subsequently published, and the notes taken by his students, among them Alice Ambrose and the late Margaret Macdonald, from (...) 1932 to 1935. These notes, now edited by Professor Ambrose, are here published, and they shed much light on Wittgenstein's philosophical development. Among the topics considered are the meaning of a word and its relation to common usage, rules of grammar and their relation to fact, the grammar of first person statements, language games, and the nature of philosophy. This volume is indispensable to any serious discussion of Wittgenstein's work. (shrink)

At the level of our platitudinous background knowledge about things, speech is the expression of thought. And understanding what such expressing involves is central to understanding the relation between thinking and speaking. Part of what it is for a speech act to express a mental state is that the speech act accurately captures the mental state and can convey to others what mental state it is. And for this to occur, the speech act at least must have propositional content that (...) somehow reflects that of the mental state, and perhaps must have other such properties as well. (shrink)

This is a unique book. It is excellently written, crammed with information, wise and a pleasure to read.' ---Daniel C. Dennett, Tufts University.

Look before you leap. - Proverb. He who hesitates is lost. - Another proverb.

When in May 1930, the Council of Trinity College, Cambridge, had to decide whether to renew Wittgenstein's research grant, it turned to Bertrand Russell for an assessment of the work Wittgenstein had been doing over the past year. His verdict: "The theories contained in this new work . . . are novel, very original and indubitably important. Whether they are true, I do not know. As a logician who likes simplicity, I should like to think that they are not, but (...) from what I have read of them I am quite sure that he ought to have an opportunity to work them out, since, when completed, they may easily prove to constitute a whole new philosophy." "[ Philosophical Remarks ] contains the seeds of Wittgenstein's later philosophy of mind and of mathematics. Principally, he here discusses the role of indispensable in language, criticizing Russell's The Analysis of Mind . He modifies the Tractatus 's picture theory of meaning by stressing that the connection between the proposition and reality is not found in the picture itself. He analyzes generality in and out of mathematics, and the notions of proof and experiment. He formulates a pain/private-language argument and discusses both behaviorism and the verifiability principle. The work is difficult but important, and it belongs in every philosophy collection."--Robert Hoffman, Philosophy "Any serious student of Wittgenstein's work will want to study his Philosophical Remarks as a transitional book between his two great masterpieces. The Remarks is thus indispensible for anyone who seeks a complete understanding of Wittgenstein's philosophy."--Leonard Linsky, American Philosophical Association. (shrink)

It has been a commonplace from the beginnings of philosophical thought that what distinguishes humans from other species is the ability to reason; reason- ing is held to be an essential characteristic of the species and one that is unique to it. The essence condition requires that all humans possess at least the capacity for reasoning and that it be exercised in many of the ordinary cases of acquiring beliefs. And uniqueness entails that non-humans cannot reason, no matter how much (...) their behavior resembles that of humans. I think that a certain specific model of reasoning has been presupposed by proponents of these claims. And there are grounds to believe that this model is inaccurate in essential respects: if reasoning does correspond to it, then few human beliefs are acquired through reason. However, given a more accurate description of what goes on in normal human reasoning, it is no longer plausible to think that only humans reason. So either the essence or the uniqueness claim must be given up. In this paper I argue for the second option. (shrink)

1. When we attribute beliefs, desires, and other states of common sense psychology to a person, or for that matter to an animal or an artifact, we are assuming or presupposing that the person or object can be treated as an intentional system. 2. An intentional system is one which is rational through and through; its beliefs are those it ought to have, given its perceptual capacities, its epistemic needs, and its biography…. Its desires are those it ought to have, (...) given its biological needs and the most practicable means of satisfying them…. And its behavior will consist of those acts that it would be rational for an agent with those beliefs and desires to perform. [beliefs + desires  action] 3. If rationality is absent, we cannot coherently ascribe beliefs at all. 4. Therefore, no experiment could demonstrate that people systematically invoke invalid or irrational inferential strategies. (shrink)

The discrepancy between English if's and the horseshoe is far from being negligible. That is not a reason for distrusting the horseshoe, which is useful so long as it is taken to mean just what it is defined to mean; and it is not a reason for distrusting our English if's, which in spite of their ambiguities are indispensable to our daily discourse. But it is a reason for distrusting the current logical pedagogy that leads students to take the two (...) as being intertranslatable. So if symbolic logic is to help us in our English arguments (and that should surely be one of its functions) it needs to be supplemented: it needs to be provided with additional symbols (presumably with the introduction of one or more primitive concepts) that will preserve the meaning of our various if's with greater accuracy. In the present paper I shall point in the direction of such a logic. I cannot undertake to develop it in a complete postulational form; but I can at least call attention to certain English locutions by which the required postulates should be guided. And I can venture to state some of the postulates using appropriate symbols. (shrink)

_ Convention_ was immediately recognized as a major contribution to the subject and its significance has remained undiminished since its first publication in 1969. Lewis analyzes social conventions as regularities in the resolution of recurring coordination problems-situations characterized by interdependent decision processes in which common interests are at stake. Conventions are contrasted with other kinds of regularity, and conventions governing systems of communication are given special attention.

The views on contradiction and consistency that Wittgenstein expressed in his later writings have met with misunderstanding and almost uniform hositility. In this paper, I trace the roots of these views by attempting to show that, in his early writings, Wittgenstein accorded a ?unique status? to tautologies and contradictions, marking them off logically from genuine propositions. This is integral both to his Tractatus project of furnishing a theory of inference, and to the enterprise of explaining the nature of the Satz (...) (statement, proposition). Wittgenstein mantained that contradictions are not false. In his early writings this surprising thesis is a consequence of his view that contradictions are not statements. In his late writings he continues to advocate the thesis, but for quite different reasons. In these late writings, I contend, Wittgenstein succeeds in making the surprising thesis plausible. (shrink)

This book emphasizes the role of semantics as a bridge between the theory of language and the theories of other cognitive capacities such as visual perception...

Thoughts and other mental states are defined by their role in a functional system. Since it is easier to determine when we have knowledge than when reasoning has occurred, Gilbert Harman attempts to answer the latter question by seeing what assumptions about reasoning would best account for when we have knowledge and when not. He describes induction as inference to the best explanation, or more precisely as a modification of beliefs that seeks to minimize change and maximize explanatory coherence. Originally (...) published in 1973. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905. (shrink)

Required reading at more than 100 colleges and universities throughout North America.

pt. 1. The proposition and its sense.--pt. 2. On logic and mathematics.

Ludwig Wittgenstein's surviving notebooks serve to show what problems were occupying him in connection with many of the paragraphs of the Tractatus which are found in them as a first draft. They serve as a testimony to the thought processes of the Austrian philosopher.

Reprint of the original, first published in 1869.

The first systematic exposition of all the central topics in the philosophy of logic, Susan Haack's book has established an international reputation for its accessibility, clarity, conciseness, orderliness, and range as well as for its thorough scholarship and careful analyses. Haack discusses the scope and purpose of logic, validity, truth-functions, quantification and ontology, names, descriptions, truth, truth-bearers, the set-theoretical and semantic paradoxes, and modality. She also explores the motivations for a whole range of non-classical systems of logic, including many-valued logics, (...) fuzzy logic, moddal and tense logics, and relevance logics. Persupposing only an elementary knowledge of formal logic, this book includes many useful summary tables and diagrams, as well as a helpful glossary of technical terms. Wide-ranging, informative, and eminently readable, this book has proven a valuable resource for generations of students and scholars in a variety of disciplines outside philosophy needing guidance on the philosophy of logic. (shrink)