2-: 6 THEORY OF KNOWLEDGE. strative knowledge nor knowledge of fact), but belief.* The probability of our belief in the regularity of natural phenomena increases, indeed, with every new verification of the assumptions based thereon ; but, as has been shown, it never rises to absolute certainty. Nevertheless inferences from experience are trustworthy and entirely sufficient for practical life, and the aim of the above skeptical deliverances was not to shake belief — only a fool or a lunatic can doubt in earnest the immutability of nature — but only to make it clear that it is mere belief, and not, as hitherto held, demon- strative or factual knowledge. Our doubt is intended to define the boundary between knowledge and belief, and to destroy that absolute confidence which is a hindrance rather than a help to investigation. We should recognize it as a wise provision of nature that the regulation of our thoughts and the belief in the objective validity of our anticipation of future events have not been confided to the weak, inconstant, inert, and fallacious reason, but to a powerful instinct. In life and action we are governed by this natural impulse, in spite of all the scruples of the skeptical reason. In Hume's earlier work his destructive critique of the idea of cause is accompanied by a deliverance in a similar strain on the concept of substance, which is not included in the shorter revision. Substances are not perceived through impressions, but only qualities and powers. The unknown something which is supposed to have qualities, or in which these are supposed to inhere, is an unnecessary fiction of the imagination. A permanent similarity of attri- butes by no means requires a self-identical support for these. A thing is nothing more than a collection of qualities, to which we give a special name because they are always found | together. The idea of substance, like the idea of cause, is: founded in a subjective habit which we erroneously objectify. The impression from which it has arisen is our inner per- ception that our thought remains constant in the repeated!
- Hume distinguishes belief as a form of knowledge from religious faith, both^
in fact and in name. In the Treatise — the passage is wanting in tht Enquiry — our conviction of the external existence of the objects of perception is also ascribed to the former, which later formed Jacobi's point of departure. Religious faith is referred to revelation.
