Artificial intelligence has the same relation to intelligence as artificial flowers have to flowers.

--- David Lorge Parnas, Software aspects of strategic defense systems, Communications of the ACM, December 1985, Vol. 28, No. 12

In context:

Artificial intelligence has the same relation to intelligence as artificial flowers have to flowers. From a distance they may appear much alike, but when closely examined they are quite different. I don’t think we can learn much about one by studying the other. AI offers no magic technology to solve our problem. Heuristic techniques do not yield systems that one can trust.