The concept of “subject”, although is present in the reflection of human sciences since the time of classical philosophy, continues to present itself as complex and highly ambiguous. In psychoanalytic theory the paradox is concretized by the high frequence of the reference to the subject (in the Freudian Works the word subject appears more than a thousand times) but Freud never specified what is meant by this term. Moreover, in contemporary psychoanalysis in particular, expressions such as subjectivation and subjectivity are frequently used, even if there is no univocal conception of what a subject is. This paper aims to highlight how the subject is a polyphonic concept and how its escape from a definition is characteristic of its dynamism and its perpetual oscillation between the extremes of its semantic field, from subjection to substance.