Susan Haack

(? - 2026)

Initially proposed as rivals of classical logic, alternative logics have become increasingly important in areas such as computer science and artificial intelligence. Fuzzy logic, in particular, has motivated major technological developments in recent years. Susan Haack's Deviant Logic provided the first extended examination of the philosophical consequences of alternative logics. In this new volume, Haack includes the complete text of Deviant Logic , as well as five additional papers that expand and update it. Two of these essays critique fuzzy logic, while three augment Deviant Logic 's treatment of deduction and logical truth. Haack also provides an extensive new foreword, brief introductions to the new essays, and an updated bibliography of recent work in these areas. Deviant Logic, Fuzzy Logic will be indispensable to students of philosophy, philosophy of science, linguistics, mathematics, and computer science, and will also prove invaluable to experienced scholars working in these fields.

Realism is multiply ambiguous. The central concern of Part 1 of this paper is to distinguish several of its many senses — four (Theoretical Realism, Cumulative Realism, Progressive Realism and Optimistic Realism) in which it refers to theses about the status of scientific theories, and five (Minimal Realism, Ambitious Absolutism, Transcendentalism, Nidealism, Scholastic Realism) in which it refers to theses about the nature of truth or truth-bearers. Because Realism has these several, largely independent, senses, the conventional wisdom that Tarski's theory of truth supports realism, and that the Meaning-Variance thesis undermines it, needs re-evaluation. The concern of the rest of the paper is to sort out in which senses the conventional wisdom, with respect to Tarski's theory (Part 2) and the Meaning-Variance thesis (Part 3), is correct.

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.

Forthright and wryly humorous, philosopher Susan Haack deploys her penetrating analytic skills on some of the most highly charged cultural and social debates of recent years. Relativism, multiculturalism, feminism, affirmative action, pragmatisms old and new, science, literature, the future of the academy and of philosophy itself—all come under her keen scrutiny in _Manifesto of a Passionate Moderate_. "The virtue of Haack's book, and I mean _virtue_ in the ethical sense, is that it embodies the attitude that it exalts... Haack's voice is urbane, sensible, passionate—the voice of philosophy that matters. How good to hear it again."—Jonathan Rauch, _Reason_ "A tough mind, confident of its power, making an art of logic... a cool mastery."—Paul R. Gross, _Wilson Quarterly_ "Few people are better able to defend the notion of truth, and in strong, clear prose, than Susan Haack... a philosopher of great distinction."—Hugh Lloyd-Jones, _National Review_ "If you relish acute observation and straight talk, this is a book to read."—_Key Reporter_ (Phi Beta Kappa) "Everywhere in this book there is the refreshing breeze of common sense, patiently but inexorably blowing."—Roger Kimball, _Times Literary Supplement_ "A refreshing alternative to the extremism that characterizes so much rhetoric today."—_Kirkus Reviews_.

THE PRESENT paper grows out of a previous paper of mine called "Fallibilism and Necessity." That paper was primarily concerned with an issue raised by Peirce’s philosophy of mathematics: whether it is possible to hold that our mathematical beliefs are fallible, while at the same time maintaining that mathematical truths are necessary. My conclusion was that fallibilism and necessity are, in fact, perfectly compatible, once one has correctly formulated what fallibilism is: the point became clear as soon as I realized that fallibilism is a thesis about our liability to error, and not a thesis about the modal status of what we believe. This conclusion prompted the train of thought that resulted in the present paper: If fallibilism has to be conceived as a thesis primarily about cognitive agents and their liability to error, a fallibilist epistemology must allow a suitably central place to the knowing subject. Now Popper, of course, is a fallibilist; and yet he criticizes "traditional epistemology" for its preoccupation with the individual who knows or believes, and urges, instead, the claims of an "epistemology without a knowing subject." So I thought it would be worthwhile to try to work out a somewhat more developed account of the role of the knowing subject in a fallibilist epistemology, and to go about this, in the first instance, by comparing and contrasting what I believe to be the most fruitful approach with that favored by Popper.

Nobody seriously doubts the possibility, or the usefulness, of finding things out; that is something we all take for granted when we inquire about our plane schedule, the state of our bank account, the best treatment for our child's illness, and so forth – a presupposition of the most ordinary, everyday looking into things as well as of the most sophisticated scientific research, not to mention of the legal system. Of course, nobody seriously doubts, either, that sometimes, instead of really looking into things, people fake, fudge, and obfuscate to avoid discovering unpalatable truths or having to give up comfortable tenets; that is something we all take for granted when we ask who paid for a reassuring study, who stands to gain from an Official Inquiry, which party an expert witness works for, and so on.Of late, however, radical feminists, multiculturalists, sociologists and rhetoricians of science, and a good many philosophers as well – though they look into questions about their plane schedules, bank accounts, medical treatments, etc., just like everyone else – profess to have seen through what the rest of us take for granted

Is truth in the law just plain truth - or something sui generis? Is a trial a search for truth? Do adversarial procedures and exclusionary rules of evidence enable, or impede, the accurate determination of factual issues? Can degrees of proof be identified with mathematical probabilities? What role can statistical evidence properly play? How can courts best handle the scientific testimony on which cases sometimes turn? How are they to distinguish reliable scientific testimony from unreliable hokum? These interdisciplinary essays explore such questions about science, proof, and truth in the law. With her characteristic clarity and verve, Haack brings her original and distinctive work in theory of knowledge and philosophy of science to bear on real-life legal issues. She includes detailed analyses of a wide variety of cases and lucid summaries of relevant scientific work, of the many roles of the scientific peer-review system, and of relevant legal developments.

Rehearing Daubert on remand from the Supreme Court, Judge Kozinski introduced a fifth "Daubert factor" of his own: that expert testimony is based on "litigation-driven science" is an indication that it is unreliable. This article explores the role this factor has played in courts' handling of scientific testimony, clears up an ambiguity in "litigation-driven" and some uncertainties in "reliable," and assesses the reasons courts have given for reading such research with suspicion. This analysis reveals that research that is litigation-driven in the stronger of the two senses distinguished is inherently less likely to be evidentially reliable; but also that it is so hard to determine whether research is litigation-driven in this strong sense that this new Daubert factor is not as helpful as Judge Kozinski imagined.

In many academic circles today, Susan Haack observes, we encounter a ‘new almost-orthodoxy’ which distrusts the notions of truth, fact and evidence and rejects such ideals as honest inquiry and respect for evidence. Supporters of this ‘Higher Dismissiveness’, noting, correctly, that ‘truth’ is very often only what the powerful have managed to get accepted as such, draw the mistaken conclusion that those who still speak of knowledge and truth are guilty of naivete and ‘white male thinking’. In this paper Haack argues that the Higher Dismissiveness is not only confused, but dangerously so

There is one truth, but many truths: i.e., one unambiguous, non-relative truth-concept, but many and various propositions that are true. One truth-concept: to say that a proposition is true is to say (not that anyone, or everyone, believes it, but) that things are as it says; but many truths: particular empirical claims, scientific theories, historical propositions, mathematical theorems, logical principles, textual interpretations, statements about what a person wants or believes or intends, about grammatical and legal rules, etc., etc. But, as Frank Ramsey once said, “There is no platitude so obvious that eminent philosophers have not denied it”; and as soon as you ask why anyone would deny that there is one truth-concept, or that there are many true propositions, it becomes apparent that my initial, simple formula disguises many complexities