20. Ideas in themselves neither true nor false.
Any idea, then, which we have in our minds, whether conformable or not to the existence of things, or to any idea in the minds of other men, cannot properly for this alone be called false. For these representations, if they have nothing in them but what is really existing in things without, cannot be thought false, being exact representations of something: nor yet if they have anything in them differing from the reality of things, can they properly be said to be false representations, or ideas of things they do not represent. But the mistake and falsehood is:
21. But are false—1. When judged agreeable to another Man’s Idea, without being so.
First, when the mind having any idea, it JUDGES and concludes it the same that is in other men’s minds, signified by the same name; or that it is conformable to the ordinary received signification or definition of that word, when indeed it is not: which is the most usual mistake in mixed modes, though other ideas also are liable to it.
22. Secondly, When judged to agree to real Existence, when they do not.
(2) When it having a complex idea made up of such a collection of simple ones as nature never puts together, it JUDGES it to agree to a species of creatures really existing; as when it joins the weight of tin to the colour, fusibility, and fixedness of gold.
23. Thirdly, When judged adequate, without being so.
(3) When in its complex idea it has united a certain number of simple ideas that do really exist together in some sort of creatures, but has also left out others as much inseparable, it JUDGES this to be a perfect complete idea of a sort of things which really it is not; v.g. having joined the ideas of substance, yellow, malleable, most heavy, and fusible, it takes that complex idea to be the complete idea of gold, when yet its peculiar fixedness, and solubility in AQUA REGIA, are as inseparable from those other ideas, or qualities, of that body as they are one from another.
24. Fourthly, When judged to represent the real Essence.
(4) The mistake is yet greater, when I JUDGE that this complex idea contains in it the real essence of any body existing; when at least it contains but some few of those properties which flow from its real essence and constitution. I say only some few of those properties; for those properties consisting mostly in the active and passive powers it has in reference to other things, all that are vulgarly known of any one body, of which the complex idea of that kind of things is usually made, are but a very few, in comparison of what a man that has several ways tried and examined it knows of that one sort of things; and all that the most expert man knows are but a few, in comparison of what are really in that body, and depend on its internal or essential constitution. The essence of a triangle lies in a very little compass, consists in a very few ideas: three lines including a space make up that essence: but the properties that flow from this essence are more than can be easily known or enumerated. So I imagine it is in substances; their real essences lie in a little compass, though the properties flowing from that internal constitution are endless.