Intuitionistic logic is presented here as part of familiar classical logic which allows mechanical extraction of programs from proofs. to make the material more accessible, basic techniques are presented first for propositional logic; Part II contains extensions to predicate logic. This material provides an introduction and a safe background for reading research literature in logic and computer science as well as advanced monographs. Readers are assumed to be familiar with basic notions of first order logic. One device for making this (...) book short was inventing new proofs of several theorems. The presentation is based on natural deduction. The topics include programming interpretation of intuitionistic logic by simply typed lambda-calculus (Curry-Howard isomorphism), negative translation of classical into intuitionistic logic, normalization of natural deductions, applications to category theory, Kripke models, algebraic and topological semantics, proof-search methods, interpolation theorem. The text developed from materal for several courses taught at Stanford University in 1992-1999. (shrink)

This is a welcome reprint of a book that continues to grow in importance.

The author presents and defends three theses: (1) "the first is that it is not profitable for us at present to do moral philosophy; that should be laid aside at any rate until we have an adequate philosophy of psychology." (2) "the second is that the concepts of obligation, And duty... And of what is morally right and wrong, And of the moral sense of 'ought', Ought to be jettisoned if this is psychologically possible...." (3) "the third thesis is that (...) the differences between the well-Known english writers on moral philosophy from sidgwick to the present day are of little importance." (staff). (shrink)

Modal propositional logic; Modal predicate logic; A survey of modal logic.

Normal propositional modal systems This first chapter has two main aims. One is to give a general account of the propositional modal systems that we shall ...

Two attitudes are possible: one, that the world is an absolute jungle and that the exercise of coercive power by rulers is only a manifestation of this; and the other, that it is both necessary and right that there should be this exercise of power, that through it the world is much less of a jungle than it could possibly be without it, so that one should in principle be glad of the existence of such power, and only take exception (...) to its unjust exercise. (shrink)

Western philosophy and science are responsible for constructing some powerful tools of investigation, aiming at discovering the truth, delivering robust explanations, verifying conjectures, showing that inferences are sound and demonstrating results conclusively. By contrast reasoning that depends on analogies has often been viewed with suspicion. Professor Lloyd first explores the origins of those Western ideals, criticises some of their excesses and redresses the balance in favour of looser, admittedly non-demonstrative analogical reasoning. For this he takes examples both from ancient Greek (...) and Chinese thought and from the materials of recent ethnography to show how different ancient and modern cultures have developed different styles of reasoning. He also develops two original but controversial ideas, that of semantic stretch and the multidimensionality of reality. (shrink)

Did science and philosophy develop differently in ancient Greece and ancient China? If so, can we say why? This book consists of a series of detailed studies of cosmology, natural philosophy, mathematics and medicine that suggest the answer to the first question is yes. To answer the second, the author relates the science produced in each ancient civilization first to the values of the society in question and then to the institutions within which the scientists and philosophers worked.

Since psychiatry remains a descriptive discipline, it is essential for its practitioners to understand how the language of psychiatry came to be formed. This important book, written by a psychiatrist-historian, traces the genesis of the descriptive categories of psychopathology and examines their interaction with the psychological and philosophical context within which they arose. The author explores particularly the language and ideas that have characterised descriptive psychopathology from the mid-nineteenth century to the present day. He presents a masterful survey of the (...) history of the main psychiatric symptoms, from the metaphysics of classical antiquity to the operational criteria of today. Tracing the evolution of concepts such as memory, consciousness, will and personality, and of symptoms ranging from catalepsy and aboulia to anxiety and self-harm, this book provides fascinating insights into the subjective nature of mental illness, and into the ideas of British, Continental and American authorities who sought to clarify and define it. (shrink)

First published in 2000. Routledge is an imprint of Taylor & Francis, an informa company.

First published in 2000. Routledge is an imprint of Taylor & Francis, an informa company.

This entirely new work guides the reader through the most basic systems of modal propositional logic up to systems of modal predicate with identity, dealing with both technical developments and discussing philosophical applications.

John Buridan was a fourteenth-century philosopher who enjoyed an enormous reputation for about two hundred years, was then totally neglected, and is now being 'rediscovered' through his relevance to contemporary work in philosophical logic. The final chapter of Buridan's Sophismata deals with problems about self-reference, and in particular with the semantic paradoxes. He offers his own distinctive solution to the well-known 'Liar Paradox' and introduces a number of other paradoxes that will be unfamiliar to most logicians. Buridan also moves on (...) from these problems to more general questions about the nature of propositions, the criteria of their truth and falsity and the concepts of validity and knowledge. This edition of that chapter is intended to make Buridan's ideas and arguments accessible to a wider range of readers. The volume should interest many philosophers, linguists and logicians, who are increasingly finding in medieval work striking anticipations of their own concerns. (shrink)

This book challenges several widespread views concerning Aristotle's methods and practices of scientific and philosophical research. Taking central topics in psychology, zoology, astronomy and politics, Professor Lloyd explores generally unrecognised tensions between Aristotle's deeply held a priori convictions and his remarkable empirical honesty in the face of complexities in the data or perceived difficult or exceptional cases. The picture that emerges of Aristotle's actual engagement in scientific research and of his own reflections on that research is substantially more complex than (...) is usually allowed. (shrink)

First published in 2000. Routledge is an imprint of Taylor & Francis, an informa company.

The following suggestions for the interpretation of Parmenides and Melissus can be grouped for convenience about one problem. This is the problem whether, as Aristotle thought and as most commentators still assume, Parmenides wrote his poem in the broad tradition of Ionian and Italian cosmology. The details of Aristotle's interpretation have been challenged over and again, but those who agree with his general assumptions take comfort from some or all of the following major arguments. First, the cosmogony which formed the (...) last part of Parmenides' poem is expressly claimed by the goddess who expounds it to have some measure of truth or reliability in its own right, and indeed the very greatest measure possible for such an attempt. Second, the earlier arguments of the goddess prepare the ground for such a cosmogony in two ways. For in the first place these arguments themselves start from assumptions derived from earlier cosmologists, and are concerned merely to work out the implications of this traditional material. And, in the second place, they end by establishing the existence of a spherical universe: the framework of the physical world can be secured by logic even if the subsequent introduction of sensible qualities or ‘powers’ into this world marks some decline in logical rigour. (shrink)

Taking a set of central issues from ancient Greek medicine and biology, this book studies firstly, the interaction between scientific theorising and folklore or popular assumptions; secondly, the ideological character of scientific inquiry. Topics of interest in the philosphy and sociology of science illuminated here include the relationship between primitive thought and early science, the roles of the consensus on the scientific community, tradition and the authority of the written text, in the development of science.

‘Saving the appearances’, , is a slogan that, in its time, stood or was made to stand for many different methodological positions in many different branches of ancient natural science. It is not my aim, in this paper, to attempt to tackle the subject as a whole. I shall concentrate on just one inquiry, astronomy. Nor, with astronomy, can I do justice to all the complexities of what was certainly one of the central methodological issues, if not the central issue, (...) in the history of ancient theoretical astronomy. I have a quite limited aim, to examine the foundations, and test the applicability, of a widespread and influential line of interpretation of ancient Greek astronomy according to which it was essentially, or at least predominantly, what we may call ‘instrumentalist’ in character—that is, broadly speaking, that Greek astronomical theories were devices or fictions put forward purely for the sake of calculations with no claims to correspond with physical reality. (shrink)

The following suggestions for the interpretation of Parmenides and Melissus can be grouped for convenience about one problem. This is the problem whether, as Aristotle thought and as most commentators still assume, Parmenides wrote his poem in the broad tradition of Ionian and Italian cosmology. The details of Aristotle's interpretation have been challenged over and again, but those who agree with his general assumptions take comfort from some or all of the following major arguments. First, the cosmogony which formed the (...) last part of Parmenides' poem is expressly claimed by the goddess who expounds it to have some measure of truth or reliability in its own right, and indeed the very greatest measure possible for such an attempt. Second, the earlier arguments of the goddess prepare the ground for such a cosmogony in two ways. For in the first place these arguments themselves start from assumptions derived from earlier cosmologists, and are concerned merely to work out the implications of this traditional material. And, in the second place, they end by establishing the existence of a spherical universe: the framework of the physical world can be secured by logic even if the subsequent introduction of sensible qualities or ‘powers’ into this world marks some decline in logical rigour. (shrink)

This book was first published in 1991. The study of ancient science and its relations with Greek philosophy has made a significant and growing contribution to our understanding of ancient thought and civilisation. This collection of articles on Greek science contains fifteen of the most important papers published by G. E. R. Lloyd in this area since 1961, together with three newer articles. The topics range over all areas and periods of Greek science, from the earliest Presocratic philosophers to Ptolemy (...) and Galen. In each case the article is preceded by an introduction that assesses scholarly debate on the topic since the original publication. Professor Lloyd also suggests modifications and developments to his own position in the light of those debates and his own further research. (shrink)