The case before us signally shows the necessity of rigorously distinguishing in thought and language between the acts or states of perceiving and of conceiving.

The gratuitous assumption or groundless statement of Locke's, that we perceive nothing but our own ideas, would never have been made, nor the fallacies flowing from it committed, had it not been for the fundamental error in the method of treating his subject which pervades his profound Essay, and which may be succinctly described to be, not keeping distinct, in thought and language, the two essentially different operations of perceiving and conceiving; and, as a part of this error, not appropriating certain terms, such as representations and ideas, exclusively to acts of conception in the absence of the objects.

With him all these terms are professedly synonymous, and indiscriminately employed.

'Having ideas and perception," he says, in one place, "are the same thing." In another, "Whatsoever the mind perceives in itself, or is the immediate object of perception, thought, or understanding, that I call idea."

Hobbes, and others before him, had shown a similar want of discrimination.

Hence it is no wonder that, as a comparison may be made and a resemblance predicated between ideas in their proper or restricted sense and external objects, these processes should be extended

to any other of the heterogeneous phenomena ranked by the Essay on Human Understanding under the same denomination.

If instead of this verbal generalisation, or rather metaphysical jumble, Locke had steadily and consistently appropriated some term to denote discerning objects through the organs of the senses (e. g. the word perceiving), and had kept it uniformly distinct from any terms employed to designate conceiving objects in their absence (e.g. having ideas or representations), his great work, admirable in the main for its sound sense, largeness of view, and profound thought, would have been exempt from some of its weakest passages, and amongst the rest from much of the perplexed speculation which I have just pointed out.*

Whether the terms here suggested are the best that could be chosen for the purpose of this discrimination, is open to question; but that some separate appellations should be employed to accomplish the same end, and should be rigorously adhered to, very few metaphysicians will probably doubt.

A similar confusion to that here pointed out pervades German philosophy, as far as I have examined it.

In his doctrine respecting the perception of

* He would never, for example, have talked of the simple idea of fluidity, which was not in the wax before, being constantly produced in it by the application of heat.

ideas our great English philosopher is in the main followed by Kant, and divers of his countrymen, as I purpose to show hereafter. It is sufficient to mention here their unhesitating and gratuitous assertion that all which we perceive are representations, and that we can never attain to the knowledge of real objects; in the statement of which doctrine it is to be lamented that the English writers who adopt it pervert the excellent word representation from its legitimate meaning, and make it bear the weight of a false assumption. But before entering on the consideration of these philosophical aberrations. I must turn my attention to the prior subtleties of Berkeley, whose theory on this subject is by far the most celebrated of all. In explaining it, as in almost all his speculations, he exhibits a strange mixture of hasty inconsideration in laying down his premises, with great acumen and specious adroitness in drawing his conclusions. He is excelled by few in the art of erecting ingenious and imposing structures on sandy foundations.

LETTER XV.

THEORIES OF PERCEPTION. - BERKELEY.

BERKELEY, in his celebrated speculations on this subject, differs from the doctrine of Locke, animadverted upon in my last letter, since, while he concurs with it in asserting that we perceive nothing but ideas, he maintains that there are no external objects at the back (so to speak) of the ideas: in other words, he regards these ideas as in no way representing independent material entities, but being themselves all that we discern and all that actually have place or exist; and he thus avoids the inconsistency I have pointed out in his illustrious predecessor.

But this, so far, is, as I have already said, merely substituting the name idea for external objects, and really leaves the question in its original state with the disadvantage of exchanging a precise for what becomes after such a process an ambiguous

term.

Berkeley, however, overlooked or was blind to this for which oversight he had in truth abundant precedents- and went on speculating as if he thought that by giving to objects the name of

ideas (a term applied both by himself and others to purely mental phenomena of a representative character) he transmuted the first into the second; that by marking both with the same sign he effected an identification of nature in the things signified.

Quietly assuming this complete identity of nature, he proceeds very logically to argue that objects being ideas and ideas being mental phenomena, they cannot exist otherwise than in a mind perceiving them, nor have any existence when not perceived a conclusion perfectly just in substance, although objectionable in expression, if the term idea is taken in its purely representative meaning, but false if that term is taken as including or signifying objects.

In the last chapter of my Theory of Reasoning I have pointed out how frequently the doctrines of philosophers owe their extravagant results to some error in the very outset of their speculations, and that this is exemplified in Berkeley's specious but utterly unsound theory of vision. It is no less exemplified in his doctrine on the present subject. The stumble from which he never recovers is made in the first sentence of his "Treatise on Human Knowledge." "It is evident," he says, "to any one who takes a survey of the objects of human knowledge that they are either ideas actually imprinted on the senses, or else such as are perceived by attending to the passions and opera