Abstract
We shall place ourselves beside Merleau-Ponty’s philosophy to shed light on the notion of concrete, which brings in it the fact and the essence, the particle and the universal, in doing so we shall be opposed to the theoretical attitude, named by Merleau-Ponty “small rationalism”, of the early twentieth century. Firstly, we shall remember how the philosopher characterizes the theoretical attitude that reduces everything that can be said about the world to the scientific. After, we shall briefly insist upon the fact that this theoretical attitude is not far from a highly naïf political attitude which is unaware of the world it belongs to. According to Merleau-Ponty, in order to understanding the rapports between the sense and the non-sense it is necessary a new conception of reason: not a reason which operates by concepts on the background of an unquestionable rationality, but a reason that considers its origins