2) That there is no good evidence for the belief that our instinctive reactions are fruits of our ancestors' education in the midst of the same environment, transmitted to us at birth.
3) That the features of our organic mental structure cannot be explained at all by our conscious intercourse with the outer environment, but must rather be understood as congenital variations, 'accidental'[526] in the first instance, but then transmitted as fixed features of the race.
On the whole, then, the account which the apriorists give of the facts is that which I defend; although I should contend (as will hereafter appear) for a naturalistic view of their cause.
The first thing I have to say is that all schools (however they otherwise differ) must allow that the elementary qualities of cold, heat, pleasure, pain, red, blue, sound, silence, etc., are original, innate, or a priori properties of our subjective nature, even though they should require the touch of experience to waken them into actual consciousness, and should slumber, to all eternity, without it.
This is so on either of the two hypotheses we may make concerning the relation of the feelings to the realities at whose touch they become alive. For in the first place, if a feeling do not mirror the reality which wakens it and to which we say it corresponds, if it mirror no reality whatever outside of the mind, it of course is a purely mental product. By its very definition it can be nothing else. But in the second place, even if it do mirror the reality exactly, still it is not that reality itself, it is a duplication of it, the result of a mental reaction. And that the mind should have the power of reacting in just that duplicate way can only be stated as a harmony between its nature and the nature of the truth outside of it, a harmony whereby it follows that the qualities of both parties match.
The originality of these elements is not, then, a question for dispute. The warfare of philosophers is exclusively relative to their forms of combination. The empiricist maintains that these forms can only follow the order of combination in which the elements were originally awakened by the impressions of the external world; the apriorists insist, on the contrary, that some modes of combination, at any rate, follow from the natures of the elements themselves, and that no amount of experience can modify this result.
WHAT IS MEANT BY EXPERIENCE?
The phrase 'organic mental structure' names the matter in dispute. Has the mind such a structure or not? Are its contents arranged from the start, or is the arrangement they may possess simply due to the shuffling of them by experience in an absolutely plastic bed? Now the first thing to make sure of is that when we talk of 'experience,' we attach a definite meaning to the word. Experience means experience of something foreign supposed to impress us, whether spontaneously or in consequence of our own exertions and acts. Impressions, as we well know, affect certain orders of sequence and coexistence, and the mind's habits copy the habits of the impressions, so that our images of things assume a time- and space-arrangement which resembles the time- and space-arrangements outside. To uniform outer coexistences and sequences correspond constant conjunctions of ideas, to fortuitous coexistences and sequences casual conjunctions of ideas. We are sure that fire will burn and water wet us, less sure that thunder will come after lightning, not at all sure whether a strange dog will bark at us or let us go by. In these ways experience moulds us every hour, and makes of our minds a mirror of the time- and space-connections between the things in the world. The principle of habit within us so fixes the copy at last that we find it difficult even to imagine how the outward order could possibly be different from what it is, and we continually divine from the present what the future is to be. These habits of transition, from one thought to another, are features of mental structure which were lacking in us at birth; we can see their growth under experience's moulding finger, and we can see how often experience undoes her own work, and for an earlier order substitutes a new one. 'The order of experience,' in this matter of the time- and space-conjunctions of things, is thus an indisputably vera causa of our forms of thought. It is our educator, our sovereign helper and friend; and its name, standing for something with so real and definite a use, ought to be kept sacred and encumbered with no vaguer meaning.