Page:Essays in Philosophy (1856).djvu/98

 of the first principles of knowledge and belief, apart from which no real progress can be made towards the philosophy of knowledge.

The issue of philosophical scepticism is the analysis of knowledge into a succession of isolated phenomena, or into a series of notions of which no one can be predicated of another. The method employed by the pyrrhonist is to show that a radical contradiction is implied in every attempt to collect phenomena into science, or even into fragments of science, thus paralyzing the grasp of those beliefs and notions which create and cement our knowledge. But although David Hume worked this sceptical method with success against a metaphysical hypothesis which resolves all knowledge into experience alone, and accounts for its entrance, and its various kinds, by means of representations, the practical part of our nature always declares, by continuing in a state of activity, that human knowledge is in itself susceptible of a consistent defence, and at all events of a relative explanation, for a sane man hardly ever acts the sceptic, at least in the affairs of this life. It is for the philosopher to reconcile the speculative and the practical part of human nature, either by giving evidence that all our beliefs and notions are explicable, or else by exhibiting those of them that are mysterious in contrast to those of them which can be explained.

To do something towards the accomplishment of this task was the aim of Dr. Reid. With a view to this, the prevalent doctrine of representative perception must be overthrown, because it is inconsistent with experience,