Now suppose that morality necessarily presupposes freedom (in the strictest sense) as a property of our will, citing a priori as data for this freedom certain original practical principles lying in our reason, which would be absolutely impossible without the presupposition of lX freedom, yet that speculative reason had proved that freedom cannot be thought at all, then that presupposition, namely the moral one, would necessarily have to yield to the other one, whose opposite contains an obvious contradiction; consequently freedom and with it morality (for the latter would contain no contradiction if freedom were not already presupposed) would have to give way to the mechanism of nature.