Abstract
This paper is about Brentano’s philosophical program in Vienna and the overall
architecture, which binds together the main parts of his philosophy. I argue that this
program is based on Brentano’s project of philosophy as science and it aims to account for
the unity of the main branches of his philosophy. The paper is divided into six parts. The
first bears on Brentano’s philosophy of history, which is an important piece of the program.
The second is on the close relationship between philosophy and science, and the third is on
Brentano’s classification of theoretical sciences. In the three remaining parts of the paper,
I examine the two main axes of the program, i.e. psychology and metaphysics, and the
question how the three normative sciences are rooted in psychology. In the conclusion, I
argue that Brentano’s theory of the four phases in the history of philosophy provides his
philosophical program with a justification.