Not in the lay mind only, but also to a wide extent throughout the realm of Science itself, there exists the belief that no matter how thoroughly research is pursued, it can never yield anything more than descriptions of whatever it may be concerned with. Undeniably, such descriptions are becoming so complicated in detail, and at the same moment so far-ranging in their applications, that they inevitably assume the aspect of more or less final explanations; and previous investigators often regarded them as being actually explanatory, finding indeed in this supposed result one of the most powerful impulses to carry their inquiries to their utmost limit. This however, it is frequently contended, is at best a short-sighted error and at worst a misleading superstition; the truth, no matter how unwelcome it may seem, being that explanation is unattainable because it is a wholly non-scientific category and ideal. If then we wish to discover any sufficient reason, any ultimate ground, any final solution, we must turn from Science to Philosophy; and even so, many sceptics do not hesitate to add, we are foredoomed to disappointment.