"I endeavour, as much as I can, to deliver myself from those fallacies which we are apt to put upon ourselves, by taking words for things. It helps not our ignorance to feign a knowledge where we have none, by making a noise with sounds without clear and distinct significations. Names made at pleasure, neither alter the nature of things, nor make us understand them, but as they are signs of, and stand for, determined ideas."--_Locke, Hum. Und._ b. ii. ch. 13, § 18. WE have now surveyed the more simple and obvious phenomena of the human mind. We have seen, first, that we have SENSATIONS; secondly, that we have IDEAS, the copies of those sensations; thirdly, that those ideas are sometimes SIMPLE, the copies of one sensation; sometimes COMPLEX, the copies of several sensations so combined as to appear not several ideas, but one idea; and, fourthly, that we have TRAINS of those ideas, or one succeeding another without end. These are simple facts of our nature, attested by experience; and my chief object in fixing upon them the attention of the reader has been, to convey to him that accurate and steady conception of them, which is requisite for the successful prosecution of the subsequent inquiries. {128} After delineating the simple and elementary states of consciousness, it follows, in order, that we should endeavour to show what is contained in those that are complex. But in all the more complicated cases of human consciousness something of the process of Naming is involved. These cases, of course, cannot be unfolded, till the artifice of Naming is made known. This, therefore, is necessarily an intermediate inquiry; and one to which it is necessary that we should devote a particular degree of attention. There are two purposes, both of great importance, for which marks of our ideas, and sensations; or signs by which they may be denoted; are necessary. One of these purposes is, That we maybe able to make known to others what passes within us. The other is, That we may secure to ourselves the knowledge of what at any preceding time has passed in our minds. The sensations and ideas of one man are hidden from all other men; unless they have recourse to some expedient for disclosing them. We cannot convey to another man our sensations and ideas directly. Our means of intercourse with other men are through their senses exclusively. We must therefore choose some SENSIBLE OBJECTS, as SIGNS of our inward feelings. If two men agree, that each shall use a certain sensible sign, when one of them means to make known to the other that he has a certain sensation, or idea, they, in this, and in no other way, can communicate a knowledge of those feelings to one another.