… Appreciation and Critique
Linked with Jean Piaget – Switzerland.
March 27, 2006: This is a revised version of two lectures presented at the Institute of Objectivist Studies Summer Seminar, Charlottesville, VA, July 7 and 8, 1997.
 Developmental psychology owes a great debt to a Swiss thinker named Jean Piaget. Without his contributions, it is fair to say that the discipline would not exist. Piaget’s active career in psychological research lasted 60 years. His output of essays and empirical studies was prodigious. If all that mattered about Piaget was that he was the first psychologist to ask children whether two equal rows of eggs still have the same number after one of the rows is stretched out; or the first to ask children how many ways there are to get from one end of a room to the other–he would have done enough to merit our admiration.
 Piaget did a good deal more, however. One of his life-long goals was to explain development in a way that avoided both “preformation” (as he called the doctrine of innate ideas) and environmental determinism. For nearly 30 years, his ideas were completely out of favor in behaviorist-dominated American universities; between 1932 and 1950 not a single one of his books was translated into English. But Piaget outlasted behaviorism, and by 1960 his ideas were being jubilantly rediscovered by American psychologists. In his old age, he battled valiantly against the nativism of Noam Chomsky and Jerry Fodor.
 He was a psychologist with a fundamentally biological orientation. He was an epistemologist who regarded empirical studies of infants, children, and adolescents as an essential source of information about the nature of knowledge. Piaget, I will argue, speaks directly to the concerns of Objectivists.
 In this article, I will sketch Piaget’s life and output, before turning to the essentials of his theory:
knowledge has a biological function, and arises out of action;
knowledge is basically “operative”–it is about change and transformation;
knowledge consists of cognitive structures;
development proceeds by the assimilation of the environment to these structures, and the accommodation of these structures to the environment;
movement to higher levels of development depends on “reflecting abstraction,” which means coming to know properties of one’s own actions, or coming to know the ways in which they are coordinated.
 … (full long text) … until .