Many-valued logics, philosophical issues in

By Humberstone, Lloyd

The first philosophically-motivated use of many-valued truth tables arose with Jan Łukasiewicz in the 1920s. What exercised Łukasiewicz was a worry that the principle of bivalence, ‘every statement ...

Fatalism

By Craig, Edward

‘Fatalism’ is sometimes used to mean the acceptance of determinism, along with a readiness to accept the consequence that there is no such thing as human freedom. The ...

Logic, philosophy of

By Forbes, Graeme

Philosophy of logic can be roughly characterized as those philosophical topics which have emerged either from the technical development of symbolic (mathematical) logic, or from the motivations that ...

Determinism and indeterminism

By Butterfield, Jeremy

Over the centuries, the doctrine of determinism has been understood, and assessed, in different ways. Since the seventeenth century, it has been commonly understood as the doctrine that ...

Determinism and indeterminism

Over the centuries, the doctrine of determinism has been understood, and assessed, in different ways. Since the seventeenth century, it has been commonly understood as the doctrine that ...

Intuitionistic logic and antirealism

By Pagin, Peter

The law of excluded middle (LEM) says that every sentence of the form A∨¬A (‘A or not A’) is logically true. This law is accepted in classical logic, ...

Polish logic

By Zygmunt, Jan

The term ‘Polish logic’ was coined by McCall to signal the important contributions to modern logic by logicians from Poland between the wars. There were several centres of ...

Logic in the second half of the twentieth century

By Cook, Roy T.; Logan, Shay Allen

By the end of the first half of the twentieth century, logic had become a mature philosophical and mathematical discipline. As happens in mature disciplines, in the second ...

Predicate calculus

By Smiley, Timothy

The predicate calculus is the dominant system of modern logic, having displaced the traditional Aristotelian syllogistic logic that had been the previous paradigm. Like Aristotle’s, it is a ...

Dummett, Michael Anthony Eardley (1925–2011)

By Taylor, Barry

For Michael Dummett, the core of philosophy lies in the theory of meaning. His exploration of meaning begins with the model proposed by Gottlob Frege, of whose work ...

Open Future, The

By Loss, Roberto

There seems to be an objective asymmetry between the past and the future. The past has already happened, and is thus settled, determinate, and ‘closed’. Instead, the future ...

Plural logic

By Oliver, Alex; Smiley, Timothy

Plural phenomena are significant and inescapable. Granted, the plural idiom is sometimes reducible to the singular, e.g. ‘2 and 3 are prime is equivalent to ‘2 is prime ...

Vagueness

By Tye, Michael

It seems obvious that there are vague ways of speaking and vague ways of thinking – saying that the weather is hot, for example. Common sense also has ...