It is generally assumed that when a man has clearly perceived agnosticism to be the only legitimate attitude of reason to rest in with regard to religion (as I will subsequently show that it is), he has thereby finished with the matter; he can go no further. The main object of this treatise is to show that such is by no means the case. He has then only begun his enquiry into the grounds and justification of religious belief. For reason is not the only attribute of man, nor is it the only faculty which he habitually employs for the ascertainment of truth. Moral and spiritual faculties are of no less importance in their respective spheres even of everyday life; faith, trust, taste, &c., are as needful in ascertaining truth as to character, beauty, &c., as is reason. Indeed we may take it that reason is concerned in ascertaining truth only where _causation_ is concerned; the appropriate organs for its ascertainment where anything else is concerned belong to the moral and spiritual region. As Herbert Spencer says, 'men of science may be divided into two classes, of which the one, well exemplified by Faraday, keeping their religion and their science absolutely separate, are unperplexed by any incongruities between them, and the other of which, occupying themselves exclusively with the facts of science, never ask what implications they have. Be it trilobite or be it double star, their thought about it is much like the thought of Peter Bell about the primrose[44].' Now, both these classes are logical, since both, as to their religion, adopt an attitude of pure agnosticism, not only in theory, but also in practice. What, however, have we to say of the third class, which Spencer does not mention, although it is, I think, the largest, viz. of those scientific men who expressly abstain from drawing a line of division between science and religion [and then judge of religion purely on the principles and by the method of science[45]]? There are two opposite casts of mind--the mechanical (scientific, &c.) and the spiritual (artistic, religious, &c.). These may alternate even in the same individual. An 'agnostic' has no hesitation--even though he himself keenly experience the latter--that the former only is worthy of trust. But a _pure_ agnostic must know better, as he will perceive that there is nothing to choose between the two in point of trustworthiness. Indeed, if choice has to be made the mystic might claim higher authority for his direct intuitions.