The analysis sets out from a text in which Jonas presents prehistoric tools as a sign of humanity. This is said to announce technical thought. From another point of view the philosophy of Jonas shows well the organic bases of freedom in its spiritual dimension. In this sense we emphasize that technology does not appear suddenly as the product of a reflecting consciousness: thought and technology maintain crossed links of causality, in which man discovers himself, and in which he accedes to a representation of his action. These two types of approach hold also for modern technology. Between abstract thought based on lived experience and the intentionality proper to action, the mediation of technical objects appears with variable transparency ...