As to a true idea (he proceeds), we have shown that it is simple or
compounded of simple ideas ; that it shows how and why something
is or has become what it is ; and that the effects of the object as
represented in the mind correspond to the reality of the object
itself.^ Which was indeed the meaning of the ancients when they
said that true knowledge proceeds from the cause to the effects ; save
that they never to my knowledge conceived, as we do here, the mind
as acting conformably to fixed laws and like an immaterial automaton.
Hence we have gained, so far as we might at the outset, the descrip-
tion of our understanding, and such a rule of true ideas as leaves us in
no fear of confounding true things with false or feigned ; neither shall
we wonder why we understand sundry things that are in no wise
subject to the imagination, while others are in the imagination which
are wholly repugnant to the understanding, and others again agree
therewith. For we know that the operations by which the works of
imagination are produced have place according to laws of their own
wholly diverse from those of the understanding, and that the mind, as
regards the imagination, is in a merely passive condition. Whence it
also appears how easily those may fall into great error who have not
been careful to distinguish between the acts of imagination and of
understanding.
1 De Int. Em. cap. lo.
