5.  Complex Ideas of Substances are real, when they agree with the existence of Things.

Thirdly, Our complex ideas of substances, being made all of them in reference to things existing without us, and intended to be representations of substances as they really are, are no further real than as they are such combinations of simple ideas as are really united, and co-exist in things without us.  On the contrary, those are fantastical which are made up of such collections of simple ideas as were really never united, never were found together in any substance:  v. g. a rational creature, consisting of a horse’s head, joined to a body of human shape, or such as the centaurs are described:  or, a body yellow, very malleable, fusible, and fixed, but lighter than common water:  or an uniform, unorganized body, consisting, as to sense, all of similar parts, with perception and voluntary motion joined to it.  Whether such substances as these can possibly exist or no, it is probable we do not know:  but be that as it will, these ideas of substances, being made conformable to no pattern existing that we know; and consisting of such collections of ideas as no substance ever showed us united together, they ought to pass with us for barely imaginary:  but much more are those complex ideas so, which contain in them any inconsistency or contradiction of their parts.

CHAPTER XXXI.

Of adequate and inadequate ideas.

1.  Adequate Ideas are such as perfectly represent their Archetypes.

Of our real ideas, some are adequate, and some are inadequate.  Those I call adequate, which perfectly represent those archetypes which the mind supposes them taken from:  which it intends them to stand for, and to which it refers them.  Inadequate ideas are such, which are but a partial or incomplete representation of those archetypes to which they are referred.  Upon which account it is plain,

2.  Adequate Ideas are such as perfectly represent their Archetypes.  Simple Ideas all adequate.

First, that all our simple ideas are adequate.  Because, being nothing but the effects of certain powers in things, fitted and ordained by God to produce such sensations in us, they cannot but be correspondent and adequate to those powers:  and we are sure they agree to the reality of things.  For, if sugar produce in us the ideas which we call whiteness and sweetness, we are sure there is a power in sugar to produce those ideas in our minds, or else they could not have been produced by it.  And so each sensation answering the power that operates on any of our senses, the idea so produced is a real idea, (and not a fiction of the mind, which has no power to produce any simple idea); and cannot but be adequate, since it ought only to answer that power:  and so all simple