Kant’s philosophical critical attitudes provoked strong reactions, not only philosophical, but the general public. Among those of his ideas, which have been provoking severe philosophical misunderstandings and controversy are: “Which in theory is not worth, that has no use in practice”, “The rights not to lie”, “against the rights of citizens to revolt”, etc. After all, the most attention in the great public was provoked by his idea about radical evil. In this short reflection, we will try to point out the main points of this philosophical misunderstanding and to make a little more explicit the concept of radical evil.