innate ideas, in philosophy, concepts present in the mind at birth as opposed to concepts arrived at through experience. The theory has been advanced at various times in the history of philosophy to secure a basis for certainty when the validity or adequacy of the observed functioning of the mind was in question. Plato, for example, asserted the inadequacy of knowledge arrived at through sense experience; the world apparent to sense was only a temporal, changing approximation of an eternal, unchanging reality. The next important occurrence of a doctrine of innate ideas, not directly based on Plato, is in the work of René Descartes. Among the ideas Descartes took to be innate were the existence of the self: cogito ergo sum [I think, therefore I am], the existence of God, and some logical propositions like, from nothing comes nothing. John Locke, objecting that the doctrine encouraged dogmatism and laziness in thinking, advanced the classic attack on innate ideas. He argued that if certain ideas were innate they would be universally held and used, which is not the case. In contemporary discussion the question of innate resources of the mind has been the subject of dispute between behavioral psychologist B. F. Skinner and linguistic theorist Noam Chomsky. Chomsky has pointed out that the learning of a language and linguistic performance cannot be adequately explained by the empirical behaviorist model.