Psychology first!

Brentano as well as many of his followers — with notable exceptions, especially Husserl — assigned to psychology a foundational role in the edifice of science, including philosophy. My suggestion in the present paper is that this view is a consequence of Brentano’s theory of intentionality. Brentano’s thesis of the intentionality of the mental, I argue, first and foremost expresses a strong epistemological position about what knowledge in general is: all knowledge, whether inner or outer, has its source in “inner perception” and hence has somehow to do with psychology. Given this, I discuss Brentano’s accounts of a priori knowledge and of the distinction between psychology and physics — which are certainly among the most original and fruitful aspects of his epistemology and his philosophy as a whole.