2. 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 ideas are adequate. It is true, the things producing in us these simple ideas are but few of them
denominated by us, as if they were only the causes of them; but as if those ideas were real beings in them. For,
though fire be called painful to the touch, whereby is signified the power of producing in us the idea of pain, yet it
is denominated also light and hot; as if light and heat were really something in the fire, more than a power to
excite these ideas in us; and therefore are called qualities in or of the fire. But these being nothing, in truth, but
powers to excite such ideas in us, I must in that sense be understood, when I speak of secondary qualities as being
in things; or of their ideas as being the objects that excite them in us. Such ways of speaking, though
accommodated to the vulgar notions, without which one cannot be well understood, yet truly signify nothing but
those powers which are in things to excite certain sensations or ideas in us. Since were there no fit organs to
receive the impressions fire makes on the sight and touch, nor a mind joined to those organs to receive the ideas of
light and heat by those impressions from the fire or sun, there would yet be no more light or heat in the world than
there would be pain if there were no sensible creature to feel it, though the sun should continue just as it is now,
and Mount AEtna flame higher than ever it did. Solidity and extension, and the termination of it, figure, with
motion and rest, whereof we have the ideas, would be really in the world as they are, whether there were any
sensible being to perceive them or no: and therefore we have reason to look on those as the real modifications of
matter, and such as are the exciting causes of all our various sensations from bodies. But this being an inquiry not
belonging to this place, I shall enter no further into it, but proceed to show what complex ideas are adequate, and
what not.
