Learning from Experience was Wilfred Bion's first major venture into metapsychology and epistemology. In this work he set out to specify how normal and psychotic minds function. To accomplish his mission, he defines certain ideas as tools of understanding. He defines a "factor" as a mental activity that is a subset, along with other factors, of a "function." "Factors are deduced not directly but by observation of functions," he claims.

The particular function that he explicates in this work, one that he elaborates throughout his later works, is the alpha function, so named to preserve it from contamination by a penumbra of preconceptions and other associations. In the course of developing his ideas about how alpha functions work, he adds an idea borrowed from Freud (1911b) "A special function was instituted which had periodically to search the external world, in order that its data might be familiar already if an urgent...