Now in this philosophy (of ethics) it seems contrary to the idea of it that we should go back to metaphysical elements in order to make the notion of duty purified from everything empirical (from every feeling) a motive of action. For what sort of notion can we form of the mighty power and herculean strength which would be sufficient to overcome the vice-breeding inclinations, if Virtue is to borrow her “arms from the armoury of metaphysics,” which is a matter of speculation that only few...