If you are looking for an answer to the question What is Artificial Intelligence? and you only have a minute, then here's the definition the Association for the Advancement of Artificial Intelligence offers on its home page: "the scientific understanding of the mechanisms underlying thought and intelligent behavior and their embodiment in machines."
However, if you are fortunate enough to have more than a minute, then please get ready to embark upon an exciting journey exploring AI (but beware, it could last a lifetime) …
McCarthy, J. | Hayes, P. J.
"A computer program capable of acting intelligently in the world must have a general representation of the world in terms of which its inputs are interpreted. Designing such a program requires commitments about what knowledge is and how it is obtained. Thus, some of the major traditional problems of philosophy arise in artificial intelligence.More specifically, we want a computer program that decides what to do by inferring in a formal language that a certain strategy will achieve its assigned goal. This requires formalizing concepts of causality, ability, and knowledge. Such formalisms are also considered in philosophical logic." - from the Introduction reprinted in Matthew Ginsberg (ed.), Readings in Nonmonotonic Reasoning, pp. 26-45, San Francisco: Morgan Kaufmann Publishers, Inc., 1987.Stanford web version. D. Michie and B. Meltzer (Eds.), Machine intelligence 4 - Edinburgh: Edinburgh University Press, 463-502
"The LISP language is designed primarily for symbolic data processing. It has been used for symbolic calculations in differential and integral calculus, electrical circuit theory, mathematical logic, game playing, and other fields of artificial intelligence.LISP is a formal mathematical language. It is therefore podsible to give a concise yet complete description of it. Such is the purpose of this first section of the manual. Other sections will describe ways of using LISP to advantage and will explain extensions of the language which make it a convenient programming system."The M.I.T. Press
This is the first clear call for the separation of knowledge and inference procedure in AI.Â In this paper McCarthy advocates using predicate logic as a declarative representation of knowledge and first-order logic as the inference procedure.Additional notes on this landmark paper at http://www-formal.stanford.edu/jmc/mcc59/mcc59.html.Bar-Hilel's comments in the discussion section from the conference are also interesting:"PROF. Y. BAR-HILLEL: Dr. McCarthy's paper belongs in the Journal of Half-Baked Ideas, the creation of which was recently proposed by Dr. I. J. Good. Dr. McCarthy will probably be the first to admit this. Before he goes on to bake his ideas fully, it might be well to give him some advice and raise some objections. He himself mentions some possible objections, but I do not think that he treats them with the full consideration they deserve; there are others he does not mention.For lack of time, I shall not go into the first part of his paper, although I think that it contains a lot of highly unclear philosophical, or pseudo-philosophical assumptions. I shall rather spend my time in commenting on the example he works out in his paper at some length. Before I start, let me voice my protest against the general assumption of Dr. McCarthy -- slightly caricatured -- that a machine, if only its program is specified with a sufficient degree of carelessness, will be able to carry out satisfactory even rather difficult tasks."In Proceedings of the Symposium on the Mechanization of Thought Processes, National Physical Laboratory 1:77-84