The chapter investigates the relation between philosophy, psychology, and phenomenology. First, it gives a brief account of Husserl’s criticism of psychologism in his Logical Investigations (Logische Untersuchungen). Then it looks at Husserl’s later distinction between a phenomenological psychology and a transcendental phenomenology. And finally, the chapter discusses the difference between a (neo-)Kantian and a phenomenological concept of transcendental philosophy.