An abridgment of Mr. Locke's Essay concerning humane [sic] understanding

CHAP. IV. Of the Reality of our Knowledge.

I Doubt not but my Reader by this time, may be apt to think that I have been all this while, only building a Castle in the Air: and be ready to ob∣ject, If it be true, that all Knowledge lies only in the perception of the Agreement or Disagreement of our own Ideas, the Visions of an Enthusiast, and the reason∣ings of a Sober Man will be equally Cer∣tain: It is no matter how Things are, so a Man observe but the Agreement of his own Imaginations, and talk conformably, It is all Truth, all Certainty, That an Harpy is not a Centaur, is by this way as certain Knowledge, and as much Truth, as that a Square is not a Circle.

But of what use is all this knowledge of Mens own imaginations, to a Man that enquires after the reality of Things?

To which I Answer, That if our know∣ledge of our Ideas should terminate in them, and reach no farther, where there is something farther intended; our most serious Thoughts would be of little more use, than the Reveries of a crazy Brain. But I hope before I have done, to make it evident, that this way of Cer∣tainty by the knowledge of our own Ideas, goes a little farther, than bare ima∣gination: and that all the certainty of ge∣neral Truths a Man has, lies in nothing else but this knowledge of our Ideas.

'Tis evident that the Mind knows not Things immediately, but by the inter∣vention of the Ideas it has of them. Our Knowledge therefore is real, only so far as there is a conformity between our Ideas, and the reality of Things. But how shall we know when our Ideas agree, with Things themselves? I Answer, There be Two sorts of Ideas that, we may be assured agree with Things: These are,

First, Simple Ideas; Which since the Mind can by no means make to it self, must be the effect of Things operating upon the Mind, in a natural way; and producing therein those Perceptions, which by the Will of our Maker, they are or∣dained and adapted to. Hence it follows, that Simple Ideas are not fictions of our Fancies, but the natural and regular pro∣ductions of Things without us, really operating upon us; which carry with them all the conformity our State re∣quires, which is to represent Things, un∣der those appearances they are fitted to produce in us. Thus the Idea of White∣ness, as it is in the Mind, exactly an∣swers that Power which is in any Body to produce it there. And this conformi∣ty between our Simple Ideas, and the ex∣istence of Things, is sufficient for real Knowledge.

Secondly, All our Complex Ideas, except those of Substances, being Archetypes, of the Mind's own making, and not referred to the Existence of Things as to their Originals, cannot want any Conformity necessary to real Knowledge. For that which is not designed to represent any thing but it self, can never be capable of

a wrong Representation. Here the Ideas themselves are considered as Archetypes, and Things no otherwise regarded, than as they are conformable to them. Thus the Mathematician considers the Truth and Properties belonging to a Rectangle or Circle only, as they are Ideas in his own Mind, which possibly he never found existing Mathematically, that is, precisely True: yet his Knowledge is not only Certain, but Real; because Re∣al Things are no farther concern'd nor intended to be meant by any such Pro∣positions, than as Things really agree to those Archetypes in his Mind. It is true of the Idea of a Triangle, that its three An∣gles are equal to two right ones; It is true also of a Triangle, wherever it Exists: what is true of those Figures, that have barely an Ideal Existence in his Mind, will hold true of them also, when they come to have a Real Existence in Mat∣ter.

Hence it follows that Moral Know∣ledge, is as capable of Real Certainty as Mathematicks. For Certainty being no∣thing but the Perception of the Agree∣ment or Disagreement of our Ideas,, and Demonstration nothing, but the Perception

of such Agreement by the intervention of other Ideas; our Moral Ideas as well as Ma∣thematical, being Archetypes themselves, and so Adequate or Complete Ideas all the Agreement or Disagreement we shall find in them, will produce Real Knowledge as well as in Mathematical Figures. That which is requisite to make our Know∣ledge Certain, is the clearness of our Ideas; and that which is required to make it Real, is, that they answer their Archetypes.

But it will here be said, That if Moral Knowledge be placed in the Contem∣plation of our own Moral Ideas; and those be of our own making, what strange Notions will there be of Justice and Tem∣perance? What confusion of Vertues and Vices, if every Man may make what Ideas of them he pleases? I Answer, No Con∣fusion, nor Disorder at all, in the Things themselves, nor the Reasonings about them; no more, than there would be a change in the Properties of Figures, and their Relations one to another, If a Man should make a Triangle with four corners, or a Trapezium with four right Angles; that is in plain English, change the Names of the Figures, and call that by

one Name, which is called ordinarily by another. The change of Name will indeed at first disturb him, who knows not what Idea, it stands for: but as soon as the Figure is drawn, the Consequences and Demonstration are plain, and clear. Just the same is it in Moral Knowledge: Let a Man have the Idea of taking from others, without their consent, what they are justly possessed of, and call this Ju∣stice, if he pleases: he that takes the Name here, without the Idea put to it, will be mistaken by joyning another Idea of his own to that Name; but strip the Idea of that Name, or take it such as it is in the Speakers Mind; and the same Things will agree to it, as if you called it Injustice.

One thing we are to take notice of, That where God, or any other Law-ma∣ker has defined any Moral Names, there they have made the Essence of that Spe∣cies to which that Name belongs: And there it is not safe to apply, or use them otherwise. But in other cases it is bare impropriety of Speech, to apply them contrary to the common usage of the Country they are used in.

Thirdly, But the Complex Ideas which we refer to Archetypes without us, may differ from them, and so our Knowledge about them may come short of being real: and thus are our Ideas of Substances. These must be taken from something, that does or has Existed, and not be made up of Ideas arbitrarily put together, without any real Pattern. Herein therefore is founded the reality of our Knowledge concerning Substances, that all our Com∣plex Ideas of them must be such, and such only, as are made up of such Simple ones, as have been discovered to co-exist in Nature. Wherever then we perceive the Agreement or Disagreement of any of our Ideas, there is Certain Know∣ledge; and wherever we are sure those Ideas agree with the reality of Things, there is Certain real Knowledge.