the authority of Wolff and Kant — we are under the stringent necessity of obtaining from Metaphysics a support for Moral Science.

Now, of all the problems that the human intellect has to grapple with, that of Metaphysics is by far the hardest; so much so that it is regarded by many thinkers as absolutely insoluble. Apart from this, in the present case, I labour under the special disadvantage which the form of a detached monograph involves. In other words, I am not at liberty to start from some definite metaphysical system, of which I may be an adherent; because, if I did, either it would have to be expounded in detail, which would take too much space; or else there would be the necessity of supposing it granted and unquestioned, — an exceedingly precarious proceeding.