The psychologist's attitude towards cognition will be so important in the sequel that we must not leave it until it is made perfectly clear.It is a thoroughgoing dualism.It supposes two elements, mind knowing and thing known, and treats them as irreducible.Neither gets out of itself or into the other, neither in any way is the other, neither makes the other.They just stand face to face in a common world, and one simply knows, or is known unto, its counterpart.This singular relation is not to be expressed in any lower terms, or translated into any more intelligible name.Some sort of signal must be given by the thing to the mind's brain, or the knowing will not occur - we find as a matter of fact that the mere existence of a thing outside the brain is not a sufficient cause for our knowing it: it must strike the brain in some way, as well as be there, to be known.But the brain being struck, the knowledge is constituted by a new construction that occurs altogether in the mind.The thing remains the same whether known or not. And when once there, the knowledge may remain there, whatever becomes of the thing.
By the ancients, and by unreflecting people perhaps today, knowledge is explained as the passage of something from without into the mind - the latter, so far, at least, as its sensible affections go, being passive and receptive.But even in mere sense-impression the duplication of the object by an inner construction must take place.Consider, with Professor Bowne, what happens when two people converse together and know each other's mind.
"No thoughts leave the mind of one and cross into the mind of the other.
When we speak of an exchange of thought, even the crudest mind knows that this is a mere figure of speech....To perceive another's thought, we must construct his thought within ourselves;...this thought is our own and is strictly original with us.At the same time we owe it to the other; and if it had not originated with him, it would probably not have originated with us.But what has the other done?...This: by an entirely mysterious world-order, the speaker is enabled to produce a series of signs which are totally unlike thought, but which, by virtue of the same mysterious order, act as a series of incitements upon the hearer, so that he constructs within himself the corresponding mental state.The act of the speaker consists in availing himself of the proper incitements.The act of the hearer is immediately only the reaction of the soul against the incitement....All communication between finite minds is of this sort....Probably no reflecting person would deny this conclusion, but when we say that what is thus true of perception of another's thought is equally true of the perception of the outer world in general, many minds will be disposed to question, and not a few will deny it outright.Yet there is no alternative but to affirm that to perceive the universe we must construct it in thought, and that our knowledge of the universe is but the unfolding of the mind's inner nature....By describing the mind as a waxen tablet, and things as impressing themselves upon it, we seem to get great insight until we think to ask where this extended tablet is, and how things stamp themselves on it, and how the percep- tive act would be explained even if they did....The immediate antecedents of sensation and perception are a series of nervous changes in the brain.
Whatever we know of the outer world is revealed only in and through these nervous changes.But these are totally unlike the objects assumed to exist as their causes.If we might conceive the mind as in the light, and in direct contact with its objects, the imagination at least would be comforted;
but when we conceive the mind as coming in contact with the outer world only in the dark chamber of the skull, and then not in contact with the objects perceived, but only with a series of nerve-changes of which, moreover, it knows nothing, it is plain that the object is a long way off.All talk of pictures, impressions, etc., ceases because of the lack of all the conditions to give such figures any meaning.It is not even clear that we shall ever find our way out of the darkness into the world of light and reality again.
We begin with complete trust in physics and the senses, and are forthwith led away from the object into a nervous labyrinth, where the object is entirely displaced by a set of nervous changes which are totally unlike anything but themselves.Finally, we land in the dark chamber of the skull.
The object has gone completely, and knowledge has not yet appeared.Nervous signs are the raw material of all knowledge of the outer world according to the most decided realism.But in order to pass beyond these signs into a knowledge of the outer world, we must posit an interpreter who shall read back these signs into their objective meaning.But that interpreter, again, must implicitly contain the meaning of the universe within itself;
and these signs are really but excitations which cause the soul to unfold what is within itself.Inasmuch as by common consent the soul communicates with the outer world only through these signs, and never comes nearer to the object than such signs can bring it, it follows that the principles of interpretation must be in the mind itself, and that the resulting construction is primarily only an expression of the mind's own nature.All reaction is of this sort; it expresses the nature of the reacting agent, and knowledge comes under the same head.this fact makes it necessary for us either to admit a pre-established harmony between the laws and nature of thought and the laws and nature of things, or else to allow that the objects of perception, the universe as it appears, are purely phenomenal, being but the way in which the mind reacts against the ground of its sensations."