Shakespeare's theories of mental illness, as expressed in his early plays, were in advance of his time; they seem to have been influenced by those of Johann Weyer, of whose writings Freud also expressed a high opinion.

By treating the content of these early plays as if they were the associations produced by a patient in psychoanalysis, some hypotheses can be constructed concerning Shakespeare himself, and some of these hypotheses are given support by examination of what is known of the dramatist's life.