But it should be remembered that Berkeley tried hard to do full justice to the world of things in which we actually find ourselves; not a hypothetical, inferred, unperceived world, but the world of the things we actually perceive. He distinguished carefully between what is real and what is merely imaginary, though he called both "ideas"; and he recognized something like a system of nature. And, by the argument from analogy which we have already examined (section 41), he inferred the existence of other finite minds and of a Divine Mind.

But just as John Locke had not completely thought out the consequences which might be deduced from his own doctrines, so Berkeley left, in his turn, an opening for a successor. It was possible for that acutest of analysts, David Hume (1711-1776), to treat him somewhat as he had treated Locke.

Among the objects of human knowledge Berkeley had included the self that perceives things. He never succeeded in making at all clear what he meant by this object; but he regarded it as a substance, and believed it to be a cause of changes in ideas, and quite different in its nature from all the ideas attributed to it. But Hume maintained that when he tried to get a good look at this self, to catch it, so to speak, and to hold it up to inspection, he could not find anything whatever save perceptions, memories, and other things of that kind. The self is, he said, "but a bundle or collection of different perceptions which succeed each other with inconceivable rapidity, and are in a perpetual flux and movement."

As for the objects of sense, our own bodies, the chairs upon which we sit, the tables at which we write, and all the rest—these, argues Hume, we are impelled by nature to think of as existing continuously, but we have no evidence whatever to prove that they do thus exist. Are not the objects of sense, after all, only sensations or impressions? Do we not experience these sensations or impressions interruptedly? Who sees or feels a table continuously day after day? If the table is but a name for the experiences in question, if we have no right to infer material things behind and distinct from such experiences, are we not forced to conclude that the existence of the things that we see and feel is an interrupted one?

Hume certainly succeeded in raising more questions than he succeeded in answering. We are compelled to admire the wonderful clearness and simplicity of his style, and the acuteness of his intellect, in every chapter. But we cannot help feeling that he does injustice to the world in which we live, even when we cannot quite see what is wrong. Does it not seem certain to science and to common sense that there is an order of nature in some sense independent of our perceptions, so that objects may be assumed to exist whether we do or do not perceive them?

When we read Hume we have a sense that we are robbed of our real external world; and his account of the mind makes us feel as a badly tied sheaf of wheat may be conceived to feel—in danger of falling apart at any moment. Berkeley we unhesitatingly call an Idealist, but whether we shall apply the name to Hume depends upon the extension we are willing to give to it. His world is a world of what we may broadly call ideas; but the tendencies of his philosophy have led some to call it a Skepticism.

50. THE REVOLT OF "COMMON SENSE."—Hume's reasonings were too important to be ignored, and his conclusions too unpalatable to satisfy those who came after him. It seemed necessary to seek a way of escape out of this world of mere ideas, which appeared to be so unsatisfactory a world. One of the most famous of such attempts was that made by the Scotchman Thomas Reid (1710-1796).

At one time Reid regarded himself as the disciple of Berkeley, but the consequences which Hume deduced from the principles laid down by the former led Reid to feel that he must build upon some wholly different foundation. He came to the conclusion that the line of philosophers from Descartes to Hume had made one capital error in assuming "that nothing is perceived but what is in the mind that perceives it."

Once admit, says Reid, that the mind perceives nothing save ideas, and we must also admit that it is impossible to prove the existence either of an external world or of a mind different from "a bundle of perceptions." Hence, Reid maintains that we perceive—not infer, but perceive—things external to the mind. He writes:[2]—

"Let a man press his hand against the table—he feels it hard. But what is the meaning of this? The meaning undoubtedly is, that he hath a certain feeling of touch, from which he concludes, without any reasoning, or comparing ideas, that there is something external really existing, whose parts stick so firmly together that they cannot be displaced without considerable force.