text: Philosophy, therefore, being theoretic, must have her doctrines. And why? Because no man can duly perform right actions except one who has been entrusted with reason, which will enable him, in all cases, to fulfil all the categories of duty. These categories he cannot observe unless he receives precepts for every occasion, and not for the present alone. Precepts by themselves are weak and, so to speak, rootless if they be assigned to the parts and not to the whole. It is the doctrines which will strengthen and support us in peace and calm, which will include simultaneously the whole of life and the
  universe in its completeness. There is the same difference between philosophical doctrines and precepts as there is between elements and members; the latter depend upon the former, while the former are the source both of the latter and of all things.