Locke, the follower of Aristotle in modern times, and Leibnitz of Plato (although he cannot be said to have imitated him in his mysticism), have not been able to bring this question to a settled conclusion.
The procedure of Epicurus in his sensual system, in which he always restricted his conclusions to the sphere of experience, was much more consequent than that of Aristotle and Locke. The latter especially, after having derived all the conceptions and principles of the mind from experience, goes so far, in the employment of these conceptions and principles, as to maintain that we can prove the existence of G.o.d and the existence of G.o.d and the immortality of them objects lying beyond the soul--both of them of possible experience--with the same force of demonstration as any mathematical proposition.
3. In relation to method. Method is procedure according to principles.
We may divide the methods at present employed in the field of inquiry into the naturalistic and the scientific. The naturalist of pure reason lays it down as his principle that common reason, without the aid of science--which he calls sound reason, or common sense--can give a more satisfactory answer to the most important questions of metaphysics than speculation is able to do. He must maintain, therefore, that we can determine the content and circ.u.mference of the moon more certainly by the naked eye, than by the aid of mathematical reasoning. But this system is mere misology reduced to principles; and, what is the most absurd thing in this doctrine, the neglect of all scientific means is paraded as a peculiar method of extending our cognition. As regards those who are naturalists because they know no better, they are certainly not to be blamed. They follow common sense, without parading their ignorance as a method which is to teach us the wonderful secret, how we are to find the truth which lies at the bottom of the well of Democritus.
Quod sapio satis est mihi, non ego curo Esse quod Arcesilas aerumnosique Solones. PERSIUS --Satirae, iii. 78-79.
is their motto, under which they may lead a pleasant and praiseworthy life, without troubling themselves with science or troubling science with them.
As regards those who wish to pursue a scientific method, they have now the choice of following either the dogmatical or the sceptical, while they are bound never to desert the systematic mode of procedure. When I mention, in relation to the former, the celebrated Wolf, and as regards the latter, David Hume, I may leave, in accordance with my present intention, all others unnamed. The critical path alone is still open.
If my reader has been kind and patient enough to accompany me on this. .h.i.therto untravelled route, he can now judge whether, if he and others will contribute their exertions towards making this narrow footpath a high road of thought, that which many centuries have failed to accomplish may not be executed before the close of the present--namely, to bring Reason to perfect contentment in regard to that which has always, but without permanent results, occupied her powers and engaged her ardent desire for knowledge.