There is a fundamental contradiction or rather tension in Sausure’d Course: between the necessity of the sign within itself and its arbitrariness within a system of signs. That tension penetrates the entire Course and generates its “plot”. It can be expressed by the quantity of information generalized to quantum information by quantum mechanics. Then the problem is how a bit to be expressed by a qubit or vice versa. The structure of the main problem of quantum mechanics is isomorphic. Thus its solution, namely the set of solutions of the Schrödinger equation, implies the solution of the above contradictionor tesnion