We use commonly science to prove the possibility or impossibility of some actions. However, science can form such judgments only within already known domains of action. Thus, Science is in trouble, and finds itself unable to cope with unestablished and undecidable propositions. It may be led to contradict itself when it faces the unknown. The clarification of this logical trap, and ways to overcome it, are given by contemporary advancements in design theory, namely the development of C-K theory 2. The purpose of such theory is to study how we can reason rigorously when we face the unknown; likewise, probability theory offered a rigorous interpretation of chance and randomness. Facing desirable unknowns, Design theory invites to reject possibility/impossibility assertions and guides the elaboration of a creative and dual expansion. 1 Hatchuel A. and Weil B., C-K design theory: An advanced formulation, Research in Engineering Design,