animals, trees, etc., the mind can frame abstract ideas of them as well as of extension or colour. Thus, the abstract idea of man includes colour and stature, but no particular colour and no particular stature.

Berkeley altogether denied the possibility of such a process, the results of which he describes as monstrous and incredible. He totally denied, for instance, that we could form the general idea of a triangle which, in Locke's words, 'must be neither oblique nor rectangle, neither equilateral, equicrural, nor scalenon, but all and none of these at once.'

His own view was that words are only symbols, and that abstract words are only the names of parts of things common to an indefinite number of particular things to which the same name is applied. 'An idea which, considered in itself, is particular, becomes general by being made to represent or stand for all other particular things of the same sort.' I draw a triangle on a piece of paper, and argue from it about all triangles, and this is perfectly legitimate so long as the triangle from which I argue has the same qualities as those about which I conclude. I take, say, a right-angled equilateral triangle as a specimen, from which I demonstrate the proposition that its three angles are equal to two right angles, and this demonstration applies to all triangles, whether right-angled and equilateral or not, inasmuch as neither of those qualities is in any way introduced into or relied

upon in the course of the demonstration.

I am

arguing, therefore, not about the abstract idea of a triangle, as described by Locke, but about one specific triangle which is the type of all figures whatever that have in common with it the property of being enclosed by three straight lines.

What, it may be asked, is the practical difference between these theories? The best answer to this is to be found in a reference to Locke's political works, and those of his disciples-Warburton, for instance, in his Alliance of Church and State. The effect of Locke's theory of abstract ideas, when applied to such topics, is to produce what has the appearance of a remarkable inconsistency with the rest of his theories. His abstract ideas become a sort of bastard innate ideas, for whether you are told that such and such things are laws of nature because they follow from the abstract idea of justice or of a State, or from the innate ideas of justice or a State, is really of very little importance.

The notion that there are such things as abstract ideas had its origin, according to Berkeley, in a misconception of the use of language. Locke's account of them was that they were 'made in order to naming,' and this he connected with the further opinion, that every word ought to have some one precise settled signification. This, said Berkeley, is not the case. 'There is no such thing as one precise and definite signification attached to any general name, they all signifying indifferently a great number

of particular ideas.' Words, in short, he regarded not as the medium by which ideas were to be raised in the mind, but rather as symbols, like the symbols of algebra, which are capable of representing an indefinite number of particular things.

By getting rid of abstract ideas Berkeley expected to simplify very materially the whole process of thought. First, he expected to get rid of all merely verbal controversies, because, as words, in his view, were only counters reducible to particular specific thoughts and not denoting abstract ideas, he would be always able to translate his language into perfectly intelligible thoughts. So long as I confine my thoughts to my own ideas divested of words I do not see how I can be easily mistaken. The objects I consider I clearly and adequately know. I cannot be deceived in thinking I have an idea which I have not. It is not possible for me to imagine that any of my own ideas are like or unlike that are not truly so. To discern the agreements or disagreements that are between my ideas, to see what ideas are included in any compound idea, and what not, there is nothing more requisite than an attentive perception of what passes in my own understanding.'

Having thus, as he considered, laid the foundation for clearness of thought in a proper theory of the functions of language and the nature of words, Berkeley proceeds to use the instrument which he has devised.

He reckons up three different sets of ideas: those which are imprinted on the senses, those which are perceived by attending to the operations of the mind, and those which are formed by the help of memory and imagination. Besides these, he says, there is the mind itself, that which knows or perceives these ideas, and which is called 'I, mind, spirit, soul, or myself' -a thing distinct from all ideas whatever, and being that wherein they exist, and whereby they are perceived.

These ideas, moreover, exist only in so far as they are perceived: 'Their esse is percipi, nor is it possible they should have any existence out of the minds, or thinking beings, which perceive them. Consequently so long as they are not actually perceived by me, or do not exist in my mind, or in that of any other created spirit, they must either have no existence at all, or else subsist in the mind of some eternal spirit, it being perfectly unintelligible to attribute to any single part of them an existence independent of a spirit. spirit. To be convinced of which the reader need only reflect, and try to separate in his own thoughts the being of a sensible thing from its being perceived.'

This is the essence of Berkeley's famous system, and, short as is the statement of it, the whole of the treatise on the principles of human knowledge, and of the Dialogues between Hylas and Philonous, is only a development of its various consequences, and an answer to the objections which may be made to it.

The phraseology of Berkeley's system is rather puzzling at first sight, and this may probably be the reason, or at least one reason, why, as Hume says, 'it admits of no answer, and produces no conviction'; but, if it is carefully examined, the system, we think, will be found to fall into a few of the very plainest propositions that ever were conceived by any human creature, as thus :—

That which we have no reason to believe to exist is to us as if it did not exist.

We have no reason to believe in the existence of anything unless we either perceive it or infer its existence from something which we do perceive.

We perceive nothing except what we perceive with our senses. The eye perceives colours, the ear sounds, the finger solidity, etc.

Every sensible object, whatever else it is, is a combination of such perceptions. Whatever else a stick may be, it is hardness+weight+a certain colour+a certain sound on being struck+a certain smell, etc.

But, besides these things, there is nothing else in the stick that we know of.

So far, therefore, as we know, the stick is a bundle of perceptions or ideas, and the notion of any substance or matter over and above the immediate objects of our senses is purely gratuitous-a mere metaphysical subtlety, the existence of which we have no more reason to believe than we have to believe, for instance, that there are gryphons in Sirius.