15. Our ideas of spiritual substances, as clear as of bodily substances.
Besides the complex ideas we have of
material sensible substances, of which I have last spoken,--by the simple ideas we have taken from those
operations of our own minds, which we experiment daily in ourselves, as thinking, understanding, willing,
knowing, and power of beginning motion, etc., co-existing in some substance, we are able to frame the complex
idea of an immaterial spirit. And thus, by putting together the ideas of thinking, perceiving, liberty, and power of
moving themselves and other things, we have as clear a perception and notion of immaterial substances as we
have of material. For putting together the ideas of thinking and willing, or the power of moving or quieting
corporeal motion, joined to substance, of which we have no distinct idea, we have the idea of an immaterial spirit;
and by putting together the ideas of coherent solid parts, and a power of being moved, joined with substance, of
which likewise we have no positive idea, we have the idea of matter. The one is as clear and distinct an idea as the
other: the idea of thinking, and moving a body, being as clear and distinct ideas as the ideas of extension, solidity,
and being moved. For our idea of substance is equally obscure, or none at all, in both; it is but a supposed I know
not what, to support those ideas we call accidents. It is for want reflection that we are apt to think that our senses
show us nothing but material things. Every act of sensation, when duly considered, gives us an equal view of both
parts of nature, the corporeal and spiritual. For whilst I know, by seeing or hearing, etc., that there is some
corporeal being without me, the object of that sensation, I do more certainly know, that there is some spiritual
being within me that sees and hears. This, I must be convinced, cannot be the action of bare insensible matter; nor
ever could be, without an immaterial thinking being.
