The history of ideas is structured by blind teleological choices that must be questioned, restoring freedom to thought. Johann Nikolaus Tetens (1736-1807) is completely ignored, yet he played a central role in the philosophical debates of eighteenth-century Germany. The texts presented here have been selected to bring his original contributions to light and put an end to preconceived notions.
Tetens discussed the early writings of Kant and influenced the Critique of Pure Reason. As a participant in the debate on the powers of the soul, he tried to show that the soul has its own perfect spontaneity. To do so, he distanced himself from both speculative dogmatism and empirical psychology. He therefore is not merely the "German Locke". Furthermore, his demonstration implies a reformulation of the Rousseauist idea of perfectibility.
It can then be considered that Tetens developed the Kantian problem of the objectivity of knowledge before Kant himself. The question is how he set out the problem, and what that teaches us.