This paper deals with the possibilities of using the ethical considerations of Baruch Spinoza in a psychotherapeutic context. I begin the interpretation by defining the basic features of Spinoza’s ethics and their connection with the whole of his philosophical system. The core of the study is the interpretation of Spinoza’s theory of affectivity and especially his concept of the transformation of passive affects into active, and what role philosophical knowledge plays in this transformation. The third part of the study then (...) tries to show how selected points of Spinoza’s introduced ideas can be useful for psychotherapeutic work. As much as the connection between philosophical ethics and psychotherapy seems obvious to many non-experts, most professionals on both sides are vehemently opposed to it. I believe that Spinoza’s thinking is an example of how the boundaries of these disciplines can be meaningfully bridged. (shrink)