Brentano’s views on psychology influenced the way philosophy was made at the beginning of the 20th century. But did this influence spread as far as to give place to Freud’s revolutionary discovery of the psychoanalytical unconscious? We know that Sigmund Freud attended enthusiastically Brentano’s lectures between 1874 and 1876. Yet, since Brentano’s name is never mentioned in Freud’s later, properly psychoanalytical writings, there is a very convincing argument for stating that Brentano had no lasting influence on Freud. Furthermore, Freud’s theory of the unconscious doesn’t seem to continue, but rather to oppose Brentano’s psychological views. Yet, as it was shown lately by a number of philosophers there are reasons to believe that Brentano had a profound influence on Freud. An attentive analysis of Freud’s vocabulary as well as his arguments against “philosophical” objections supports this point rather convincingly. However, Freud was not a philosopher and Brentano’s historical influence does not suffice to transform the Freudian unconscious in a philosophical concept. It is the purpose of this paper to sketch a way to make a philosophical use of Freud’s unconscious by reconstructing the dialogue between Brentano and Freud on a conceptual level. First, I will explain the differences between Brentano and Freud’s psychology. While Brentano and even the most original of his students thought the mind is entirely conscious, and they only called “unconscious” certain intermittences of this consciousness, Freud’s metapsychology rests on the supposition that the mind is primarily unconscious and it is consciousness that appears locally as a quality of certain mental events. In the second part of my paper I will show that this opposition is not as radical as it seems. Freud’s metapsychological supposition of an unconscious mind is not merely stated but proven by clinical facts. And these facts allow Freud to substitute a dynamic approach of the mental to a descriptive psychology of Brentanian inspiration: a mental state is only conscious because it becomes thus by passing from an unconscious to a conscious state. It is this change in the point of view that allows Freud to see mental events as processes rather than mere states. Thus, the results of Brentano’s descriptive psychology are not denied but rather completed by Freud’s dynamic theory of the unconscious. The purpose of this paper is thus to clarify not only Freud’s historical relation to Brentano, but also the relation of his metapsychology to Brentano’s descriptive psychology and to all psychology that takes Freud’s discovery of the unconscious seriously. Despite the explicit critique of the unconscious that we find in the Psychology from an Empirical Standpoint, I think that Freud never truly opposed Brentano. He rather took Brentano’s descriptive psychology a step further: he introduced a dynamic component to the analysis of the psyche that could throw light on the blind spots in Brentano’s psychology.