The function of reason is to dominate experience; and obviously openness to new impressions is no less necessary to that end than is the possession of principles by which new impressions may be interpreted.
CHAPTER IX—HOW THOUGHT IS PRACTICAL
Functional relations of mind and body.
Nothing is more natural or more congruous with all the analogies of experience than that animals should feel and think. The relation of mind to body, of reason to nature, seems to be actually this: when bodies have reached a certain complexity and vital equilibrium, a sense begins to inhabit them which is focussed upon the preservation of that body and on its reproduction. This sense, as it becomes reflective and expressive of physical welfare, points more and more to its own persistence and harmony, and generates the Life of Reason. Nature is reason's basis and theme; reason is nature's consciousness; and, from the point of view of that consciousness when it has arisen, reason is also nature's justification and goal.
To separate things so closely bound together as are mind and body, reason and nature, is consequently a violent and artificial divorce, and a man of judgment will instinctively discredit any philosophy in which it is decreed. But to avoid divorce it is well first to avoid unnatural unions, and not to attribute to our two elements, which must be partners for life, relations repugnant to their respective natures and offices. Now the body is an instrument, the mind its function, the witness and reward of its operation. Mind is the body's entelechy, a value which accrues to the body when it has reached a certain perfection, of which it would be a pity, so to speak, that it should remain unconscious; so that while the body feeds the mind the mind perfects the body, lifting it and all its natural relations and impulses into the moral world, into the sphere of interests and ideas.
No connection could be closer than this reciprocal involution, as nature and life reveal it; but the connection is natural, not dialectical. The union will be denaturalised and, so far as philosophy goes, actually destroyed, if we seek to carry it on into logical equivalence. If we isolate the terms mind and body and study the inward implications of each apart, we shall never discover the other. That matter cannot, by transposition of its particles, become what we call consciousness, is an admitted truth; that mind cannot become its own occasions or determine its own march, though it be a truth not recognised by all philosophers, is in itself no less obvious. Matter, dialectically studied, makes consciousness seem a superfluous and unaccountable addendum; mind, studied in the same way, makes nature an embarrassing idea, a figment which ought to be subservient to conscious aims and perfectly transparent, but which remains opaque and overwhelming. In order to escape these sophistications, it suffices to revert to immediate observation and state the question in its proper terms: nature lives, and perception is a private echo and response to ambient motions. The soul is the voice of the body's interests; in watching them a man defines the world that sustains him and that conditions all his satisfactions. In discerning his origin he christens Nature by the eloquent name of mother, under which title she enters the universe of discourse. Simultaneously he discerns his own existence and marks off the inner region of his dreams. And it behooves him not to obliterate these discoveries. By trying to give his mind false points of attachment in nature he would disfigure not only nature but also that reason which is so much the essence of his life.
They form one natural life.
Consciousness, then, is the expression of bodily life and the seat of all its values. Its place in the natural world is like that of its own ideal products, art, religion, or science; it translates natural relations into synthetic and ideal symbols by which things are interpreted with reference to the interests of consciousness itself. This representation is also an existence and has its place along with all other existences in the bosom of nature. In this sense its connection with its organs, and with all that affects the body or that the body affects, is a natural connection. If the word cause did not suggest dialectical bonds we might innocently say that thought was a link in the chain of natural causes. It is at least a link in the chain of natural events; for it has determinate antecedents in the brain and senses and determinate consequents in actions and words. But this dependence and this efficacy have nothing logical about them; they are habitual collocations in the world, like lightning and thunder. A more minute inspection of psycho-physical processes, were it practicable, would doubtless disclose undreamed of complexities and harmonies in them; the mathematical and dynamic relations of stimulus and sensation might perhaps be formulated with precision. But the terms used in the equation, their quality and inward habit, would always remain data which the naturalist would have to assume after having learned them by inspection. Movement could never be deduced dialectically or graphically from thought nor thought from movement. Indeed no natural relation is in a different case. Neither gravity, nor chemical reaction, nor life and reproduction, nor time, space, and motion themselves are logically deducible, nor intelligible in terms of their limits. The phenomena have to be accepted at their face value and allowed to retain a certain empirical complexity; otherwise the seed of all science is sterilised and calculation cannot proceed for want of discernible and pregnant elements.
How fine nature's habits may be, where repetition begins, and down to what depth a mathematical treatment can penetrate, is a question for the natural sciences to solve. Whether consciousness, for instance, accompanies vegetative life, or even all motion, is a point to be decided solely by empirical analogy. When the exact physical conditions of thought are discovered in man, we may infer how far thought is diffused through the universe, for it will be coextensive with the conditions it will have been shown to have. Now, in a very rough way, we know already what these conditions are. They are first the existence of an organic body and then its possession of adaptable instincts, of instincts that can be modified by experience. This capacity is what an observer calls intelligence; docility is the observable half of reason. When an animal winces at a blow and readjusts his pose, we say he feels; and we say he thinks when we see him brooding over his impressions, and find him launching into a new course of action after a silent decoction of his potential impulses. Conversely, when observation covers both the mental and the physical process, that is, in our own experience, we find that felt impulses, the conceived objects for which they make, and the values they determine are all correlated with animal instincts and external impressions. A desire is the inward sign of a physical proclivity to act, an image in sense is the sign in most cases of some material object in the environment and always, we may presume, of some cerebral change. The brain seems to simmer like a caldron in which all sorts of matters are perpetually transforming themselves into all sorts of shapes. When this cerebral reorganisation is pertinent to the external situation and renders the man, when he resumes action, more a master of his world, the accompanying thought is said to be practical; for it brings a consciousness of power and an earnest of success.
Cerebral processes are of course largely hypothetical. Theory suggests their existence, and experience can verify that theory only in an indirect and imperfect manner. The addition of a physical substratum to all thinking is only a scientific expedient, a hypothesis expressing the faith that nature is mechanically intelligible even beyond the reaches of minute verification. The accompanying consciousness, on the other hand, is something intimately felt by each man in his own person; it is a portion