Problems of Life and Mind. Second series, George Henry Lewes [e book reading free TXT] 📗

16. The recognition of special differences is no denial of fundamental identities. We do not deny the presence of phenomena in organisms which belong to physical and chemical agencies, but we assert that organisms have other phenomena besides these, dependent on conditions not present in physical and chemical phenomena. The same material elements and forces may be recognized in a moving inorganic body, and a moving organic body; but in the latter there is a speciality of combination with a speciality of result. Just as the same words and laws of grammatical construction may be recognized in prose and poetry; yet poetry is not prose, but has special rules of its own, and special effects. In an organism, as in a machine, the adjustment of the parts is a condition of the mechanical action; the one enables us to explain the other. But the parts adjusted, and the consequences of the adjustment, are unlike in the two cases. This unlikeness is pervading and profound. One cardinal difference is that the combination of the parts is in the machine a fixed, in the organism a fluctuating adjustment; and this fluctuation is due to certain vital processes subjectively known as sensitive guidance. Hence machines have fixed and calculated mechanisms; whereas organisms are variable and to a great extent incalculable mechanisms.

17. I conceive, therefore, that a theory which reduces vital activities to purely physical processes is self-condemned. Not that we are to admit the agency of any extra-organic principle, such as the hypothesis of Vitalism assumes (Prob. I. § 14); but only the agency of an intra-organic principle, or the abstract symbol of all the co-operant conditions—the special combination of forces which result in organization. This assures us that an organism is a peculiar kind of mechanism, the processes in which are peculiar to it; and among those processes there is one which results in what we call Sensibility. This Sensibility is a factor which raises the phenomena into another order. To overlook its presence is fatal to any explanation of the organic mechanism. Yet it is overlooked by those who tell us that when an impression on a nerve is conveyed to the brain, and is thence reflected on the limbs—as when the retina of a wolf is stimulated by the image of a sheep, and the spring of the wolf upon the sheep follows as a “purely mechanical consequence—the whole process has from first to last been physical.” Unless the term physical is here used to designate the objective sequence, as contemplated by an onlooker, who likens the process to the sequence observable in a machine, I should say that from first to last the process has been not physical, but vital, involving among its essential conditions the peculiarly vital factor named Sensibility. The process taking place in the wolf’s organism is one which involves conditions never found in purely physical processes. We may indeed analytically disregard these. We may view the process in its purely physical relations, or in its purely chemical relations, or in its purely mathematical (mechanical) relations. But this is the artifice of the analytical method. In reality the process is no one of these, for it is all of these; it is a process in a living organism, and depends on conditions only found in living organisms—nay, in this particular case the process depends on conditions only found in organisms like that of the wolf; for the image of the sheep will stimulate the brain of a goat, horse, or elephant without producing any such movement in the organism.

18. The importance of this point must excuse my reiteration of it. We must make clear to ourselves that the organism is in its objective aspect a physiological mechanism, in its subjective aspect a psychological mechanism: in both aspects it is to be radically demarcated from all inorganic mechanisms. In it the combination and co-ordination of movements involve conditions never present in machines; among these conditions, there are combinations and co-ordinations of Sensibility, which, although material processes on the objective side, are processes believed to be only present in organisms. We have the strongest reasons for concluding that every feeling, every change in Sensibility, has its correlative material process in the organism—is, in short, only the subjective aspect of the objective organic change. What in Physiology is called Co-ordination and has reference to movements, in Psychology may be called Logic, having reference to feelings. But be this latter point accepted or rejected, the one point which admits of no dispute is that an organism is radically distinguishable from every inorganic mechanism in that it acquires through the very exercise of its primary constitution, a new constitution with new powers. Its adjustment is a changing and developing mechanism. That is to say, a machine, however complex its structure, is constructed once for all, and this primary constitution is final, the adjustment of parts remaining unaltered; and although by exercise the machine may come to work more easily, with less friction, it never comes to work differently, to readjust its parts, and develop new capabilities. It has no historical factor manifest in its functions. It has no experience. It reacts at last as at first. How different the organism! This has not only variable adjustments due to internal fluctuations, it has experience which develops new parts, and new adjustments of old parts. Every organism has its primary constitution in the adjustment of parts peculiar to the species; it has also its secondary or modified constitution, in the adjustment which has been more or less altered by individual experiences; it has, thirdly, its temporary constitution in the variable adjustment due to the varying state of tension which results from varying stimulation.

19. A word on each. There is a structural disposition of the parts which is common to large groups of organisms, so that a corresponding similarity is observable in the reactions of these organisms. Thus all quadrupeds use their limbs for locomotion in very similar ways; birds use their wings for flight in similar ways. All vertebrates swallow their food, defend themselves, shrink when hurt, etc., in ways that are very similar. In so far as their organizations are alike, their actions and reactions are alike. In so far as their organizations differ, their actions and reactions differ. The goose and the vulture are alike in the main lines of structure; still more alike are duck and hen; yet, owing to certain unlike characters of structure, they manifest some marked differences in action and reaction: the goose will starve in the presence of food which the vulture gluttonously devours, and the vulture will refuse the vegetable food which the goose devours; the duck plunges into the water, the hen not only refuses to enter it, but is greatly agitated when she sees the ducklings she has hatched plunging into it. That peculiar instincts, habits, and feelings are rigorously determined by peculiarities in the organism, no one doubts, when animals are in question. If this is less obvious in the case of men, the reason is that there the influence of other factors somewhat masks the operation of the primary constitution—these factors are the modified and the temporary constitutions. Yet even in man it is true to say that his feelings and actions are the result of his organization, native and acquired.

20. No two men are organized in all respects alike. There are individual variations in structure, both native and acquired. These may be too slight to be appreciable by any other test than the difference of reaction under similar external stimuli; but the variations in the sensibility to music, color, temperature, sexual influence, moral influence, etc., betray corresponding differences in the organisms. Any one variation in structure, seemingly trivial, may be the origin of well-marked diversity in physical and moral characters. Compare the bull with the ox, or the predatory aggressive eagle with the cowardly vulture. Nor are the temporary modifications to be overlooked. Antoine Cros mentions the case of a patient, a young girl, suffering from congested liver and spleen, which of course altered the state of her blood, and thus for a time modified her constitution. Her moral character was greatly altered by it. She ceased to feel any affection for father or mother; would play with her doll, but could not be brought to show any delight in it; could not be drawn out of her apathetic sadness. Things which previously had made her shriek with laughter, now left her uninterested. Her temper changed, became capricious and violent.207 Congestion of the lungs, if unaccompanied by congestion of the liver, never produces such effects, because not thus altering the blood. The effects of liver congestion are familiar. Cros cites the case of a magistrate whose liver was enlarged, and whose skin showed a markedly bilious aspect, and in whom all affection seemed to be dead: he did not exhibit any perversion or violence, only want of emotive reaction. If he went to the theatre he could not feel the slightest pleasure in it. The thoughts of his home, his absent wife and children, were, he declared, as unaffecting to him as a problem in Euclid.

21. Owing to the recognized dependence of peculiar instincts and modes of reaction on peculiarities of structure, comparative anatomists are quite confident, when they find a portion of a skull with two occipital condyles, that the animal to which this skull belonged had red blood-corpuscles without nuclei, and (if a female) suckled its young. If in that fragment of skull there remain a single tooth, it will prove that the animal was carnivorous or herbivorous, and had, or had not, retractile claws. From such data a general conclusion may be formed as to the instincts and habits of the animal. The data disclose much of the primary constitution, that is to say, the mechanism which the animal brought with it into the world, ready prepared to react in definite ways on being stimulated. The connate mechanism has correlative tendencies of reaction. Some of these tendencies are inevitably called into play by external conditions, and they continue unaltered amid great varieties of circumstances, provided none of these variations directly deprive them of their appropriate stimulation. Such tendencies of the connate mechanism are styled automatic (an unfortunate metaphor, which has led to the theory of Automatism), and include, besides the visceral reactions, the more complex reactions of winking, breathing, swallowing, coughing, flying, walking, etc. It is true that we learn to walk, and learn to wink, whereas the other actions require no tentative efforts directed by experience; but the mechanism of all these actions is already laid down in the primary constitution, and is inevitably called into play.

22. The instincts also belong to the connate mechanism, and in the course of the normal experience of the animal inevitably come into play; but, unlike the automatic tendencies of breathing, swallowing, and coughing, they are capable of modification, or even suppression, by alterations in the course of individual experience. The connate mechanism of the cat determines its dread of water, and its enmity to the dog and mouse; yet a cat will by the modifications of certain experiences become as ready as an otter to take to the water, and become so fond of a dog that she will allow him to tend upon her kittens; and so indifferent to the mouse that she will let it run over her body. All this implies a new adjustment in the nervous centres, with new modes of reaction on sensory impressions: the inherited mechanism has been modified. I need not dwell on the profound modifications which the human inherited mechanism undergoes in the course of experience—how social influences and moral and