Acknowledgements; abduction; Abelard Peter; Absolute; absolute consistency; absolute inconsistency; absolutism; absorption; abstract class; abstract data type; abstract interpretation; abstraction; abstractionism; abstract machine; Abstract Machine Notation; abstract syntax; abstract syntax tree; Abstract-Type and Scheme-Definition Language; absurd; Abunaser; accent fallacy of; Acceptable Use Policy; acceptance testing; acceptor; access consciousness; accident; accidentalism; accident fallacy of; accuracy; a-consciousness; acronym; action; action theory; active object; actor; Actors; act - rule utilitarianism; actual; actuality - potentiality; adaptive learning; Addams Jane; addition; additive; ad hoc; ad hominem argument; adiaphora; A Dictionary of Philosophical Terms and Names; adjectival numerals; Adler Alfred; Adorno Theodor Wiesengrund; aesthetic; aestheticism; aesthetics; affirmative action; affirmative conclusion from negative premise; affirmative proposition; affirming the alternative; affirming the consequent; a fortiori; agent; aggregate type; aggregation; agnosticism; agreement method of; AI; AI-complete; aisthaesis; aition; aka; akrasia; AL; Albert the Great; aleph 0; aletheia; Alexander Samuel; Algazel; algebra; algebraic; algebraic data type; algebraic structure; algorithm; Algorithmic Model; alias; aliasing; alienation; alife; A-Life; alpha-categoricity; alphanumeric; Alpharabius; alternation; alternative occurrence; Althusser Louis; altruism; ambiguity; Amdahl's Law; amoral; amphiboly; analog; analogue; analogue computer; analogy; analysis; analytic; Analytical Engine; Analytical Machine; analytic philosophy; analytic - synthetic; anamnaesis; anankae; anarchism; Anaxagoras of Clazomenae; Anaximander; Anaximenes; AND; andreia; Angst; anima; animal rights; animals; animism; annealing; anomalous monism; Anscombe G.E.M.; Anselm - Anselm of Canterbury; antecedent; Anthony Susan Brownell; anthropic principle; anthropomorphism; antichain; antinomy; Antisthenes; antisymmetric; antitheorem; antithesis; anxiety; apeiron; APF; A Philosophical Glossary; apodeictic; apodosis; aporia; a posteriori; appearance - reality; apperception; Appiah Kwame Anthony; applied ethics; approximation algorithm; a priori; A proposition; Aquinas Thomas; archae; Archimedes; architecture; Arendt Hannah; Ares; aretae; arg; argument; argument form; argument from evil; argumentum; argumentum ad populum; Aristippus; aristocracy; aristotelianism; aristotelian logic; Aristotle; arithmetic, formal system of; arithmetisation; arity; Armstrong David M.; Arnauld Antoine; Arrow Kenneth Joseph; artificial intelligence; Artificial Life; artificial neural network; asceticism; aspectual shape; assent; assertion; assertoric; assignment; assignment problem; associated propositional formula; association; associationalism; association of ideas; assumption; ataraxia; atheism; atom; atomism; attribute; Aufklaerung; Augustine; Austin John; Austin John Langshaw; authentication; authenticity; authoritarianism; authority appeal to; autocracy; automata; automata theory; automation; automatism; automaton; autonomy; autonomy - heteronomy of the will; avatar; Averroes; Avicebron; Avicenna; axiology; axiom; axiomatic semantics; axiomatic set theory; Axiom of Choice; Axiom of Comprehension; Ayer Alfred Jules;