Hypatia (c.370–415), Greek Neoplatonist philosopher who lived and taught in Alexandria....

hypostasis (from Latin, 'substance'), the process of regarding a concept or...

hypostatize See HYPOSTASIS.

hypothetical consent See CONTRACTARIANISM.

hypothetical construct See OPERATIONALISM.

hypothetical imperative See KANT.

hypothetical syllogism See SYLLOGISM.

hypothetico-deductive method a method of testing hypotheses. Thought to be preferable to...

Iamblichus See COMMENTARIES ON PLATO, NEOPLA-. TONIS. Ibn Baajja, Abu Bakr,...

Ibn Daud Abraham, also called Rabad (c.1110– 80), Spanish Jewish historian and...

Ibn Gabirol Solomon, in Latin, Avicebron (c.1020–c.1057), Spanish Jewish philosopher and poet,...

Ibn Khaldun 'Abdurrahman (1332–1406), Arab historian, scholar, and politician, the first thinker...

Ibn Rushd See AVERROES.

Ibn Siinaa See AVICENNA.

Ibn Tufayl Abu Bakr (d.1186), Spanish Islamic philosopher who played an important...

I-Ching ('Book of Changes'), a Chinese divination manual that may have...

icon See PEIRCE.

id See FREUD.

idea in the seventeenth and eighteenth centuries, whatever is immediately before...

idea, clear and distinct See DESCARTES.

idea, innate See IDEA.

idealism, Critical See KANT.

idealism, transcendental See KANT.

ideal language a system of notation that would correct perceived deficiencies of...

ideal market a hypothetical market, used as a tool of economic analysis,...

ideal mathematics See HILBERT'S PROGRAM.

ideal observer a hypothetical being, possessed of various qualities and traits, whose...

ideal proposition See HILBERT's PROGRAM.

ideal type See MOSCA, WEBER.

ideal utilitarianism See RASHDALL, UTILITARIANISM.