This entry is focused on that system of thought that the German philosopher and psychologist William Stern (1871–1938) developed under the name “critical personalism.” Noted for contextual relevance at the outset is Stern’s firm agreement with a small minority of his disciplinary contemporaries that psychology should maintain strong intellectual ties with philosophy. The discussion then turns to critical personalism proper, beginning with the distinction between persons and things on which all of critical personalism is based, and continuing with a presentation of the basic theoretical concepts in terms of which the critical personalist understands the psychological life of persons and the dynamics of persons’ interactions with one another. Highlighted next are selected commentaries on critical personalism published during Stern’s time. The discussion concludes with a statement on the prospects for renewed attention to critical personalism in the twenty-first century.