NON NISI AMOR PLENE CAPIAT QUAE SUNT DIVINA.GUGLIELMO DI SAINT-THIERRY E LA GRAMMATICA DELLA VOLONTÀ.

William of Saint-Thierry takes in an interesting manner the Augustinian theme of man as imago Dei: it is linked to tradition, but in original terms, which are clearly inspired by monastic philosophy and by the new "humanist" reflections of XII century. According to William the need to renew the similarity between God and man, is the growth of love, which leads to a strong identity with God. It seems to go beyond the unity of the Augustinian tripartite structure of the human soul - memory, intelligence and will- to emphasize the importance of the will, wich is the intentio of love and knowledge. The relationship with God is the most important topic of William's thought and the power of love becomes the essential tool of the Itinerarium mentis in Deum, whose aim is to join the only level of reality that gives meaning to the world. Going through the major stages of William's life and analyzing his books, we can see that he is an iconic figure, not only for his philosophical reflection, but also for his role in the debates. He also studies at the cathedral school, he learns how to use dialectic and he is able to compete in a particular way with Abelard and with the masters of Chartres. The monk of Signy understands the need to seek a more rigorous language to speak about divine realities; but he also sees limits and errors: William opposes a different and "proper" use of reason in cognitive process, against the rationalism, that is exaggerated and falsely innovative according to him.