Thomas Aquinas

“ I answer that, Since law is the art, as it were, of directing or ordering the life of man, as in every art there is a distinct division in the rules of art, so, in every law, there must be a distinct division of precepts: else the law would be rendered useless by confusion. We must therefore say that the judicial precepts of the Old Law, whereby men were directed in their relations to one another, are subject to division according to the divers ways in which man is directed. ”

“ Even in those precepts which direct us to God, some are moral precepts, which the reason itself dictates when it is quickened by faith; such as that God is to be loved and worshipped. There are also ceremonial precepts, which have no binding force except in virtue of their Divine institution. Now God is concerned not only with the sacrifices that are offered to Him, but also with whatever relates to the fitness of those who offer sacrifices to Him and worship Him. ”

“ Because men are ordained to God as to their end; wherefore it concerns God and, consequently, is a matter of ceremonial precept, that man should show some fitness for the divine worship. On the other hand, man is not ordained to his neighbor as to his end, so as to need to be disposed in himself with regard to his neighbor, for such is the relationship of a slave to his master, since a slave "is his master's in all that he is," as the Philosopher says (Polit. i, 2) . ”