Consequently, even if it were to be proven that the human species had not advanced a single step from its first beginnings to the present day, but had instead always fallen further behind; even if one could derive from the natural predispositions of the human species a mechanical law, according to which our species always had to relapse (which, however, is far more than could ever be established): even if all this were the case, we would still not be permitted nor be able to give up that belief in human perfectibility that is implanted in us inwardly and inextinguishably.