PART THIRD.

THE CAUSES.

Die Materialisten bemühen sich zu zeigen dass alle Phænomene, auch die geistigen, physisch sind: mit Recht; nur sehen sie nicht ein, dass alles Physiche andererseits zugleich ein Metaphysisches ist.-Schopenhauer.

4

CHAPTER I.

GENERAL RELATIONS BETWEEN THE PHYSICAL AND THE MORAL.

I.

To inquire into causes we must hazard hypotheses. This cannot be avoided; for though science begins with the investigation of laws, it is perfected only in the determination of causes. Here, too, as in every experimental study, we have only to deal with. secondary and immediate causes, or, in plainer terms, with invariable antecedents. As far as our purpose is concerned, to explain physiological heredity means to define an aggregate of conditions, of such a nature that if these conditions are present heredity necessarily follows, and when they are wanting heredity is invariably wanting. In what follows, therefore, there is no question of ultimate causes; and, without inquiring here whether they are accessible or inaccessible to the human mind, we shall never speak of them except with the admission that we are entering on hypotheses.

Heredity is only a special case of the great problem of the relations between physics and morals, as will more clearly appear in the course of this work. We can, however, note in advance, in a more precise way, the position of our question, by observing that every inquiry into the relations between physics and morals necessarily comprises two parts, the influence of the moral on the physical, and the influence of the physical on the moral. The problem of heredity is concerned only with the latter. The influence of physics on morals manifests itself in many ways, of which we here consider one only, heredity. With this explanation we can now indicate the line of inquiry we shall follow in our study of causes.

We shall, in the first place, examine in a very general way the relations between the physical and the moral, as the problem in its most general form necessarily governs all the particular cases.

Then, passing from the abstract to the concrete, from theory to experience, we shall strive to show that every mental state implies a corresponding physical state.

Thence we shall draw the conclusion that an habitual mental state, such as psychological heredity, must have as its condition an habitual physical state, such as physiological heredity.

It was

In the seventeenth century, the question of the 'union of soul and body' was put in a form which rendered it insoluble. a problem of metaphysics. There were held to be two substances, body and mind; between the two an abyss. All their characteristics were opposed; then, as was to have been expected, it was found impossible to join together again what had been so thoroughly sundered.

Since the time when the progress of physiology showed that the nervous system is the physical condition of moral phenomena, and that every variation in the one is coupled with a variation in the other, researches into the correlation of the physical and the moral have had a firm basis, for the reason that it has been possible to rest them on a something which is the body, even while it is the instrument of the soul. Thus is explained the invasion, ever widening since the seventeenth century, of neurology into psychology.

Nor is this all. A further step in progress, which now appears to have been made by all partisans of experimental inquiry, consists in substituting for the metaphysical the experimental point of view, and for the antithesis of two substances the antithesis of two groups of phenomena. Hence the problem is no longer the relations between body and soul, but the relations between a group of phenomena pertaining to the unit which we call life, and the group pertaining to the unit called the ego. It is true that this way of putting the question simplifies it only by making it insoluble; for when we restrict ourselves to experience, we renounce in advance all ultimate and absolute reason. But as the experimental sciences are strictly speaking made up of two things-facts and hypotheses-and as the human mind has an invincible tendency always to sacrifice the facts to the hypotheses, we, if we resist this tendency, run the risk of throwing away the booty for its shadow.

For us, who desire as far as possible to adhere to facts, it is clear that we can examine the general relations of the physical and moral only under the experimental form. But when we try to state the question without any of the prejudices of the average mind, which render it equivocal, or of metaphysics, which render it insoluble, the only tolerably precise formula we get is this: We distinguish in ourselves two groups of phenomena or operations; those in one group are conceived as external, unconscious, subject to the twofold condition of space and time; those in the other as conscious, internal, and successive. The correlation which we discern between the two groups consists in this, that certain modes of existence in one group are the habitual antecedents of certain modes of existence in the other; for example, that sum of states of consciousness which we call a pain is accompanied by certain states of the organism, motion, play of the physiognomy, states of the viscera, and vice versa. A little belladonna, opium, or even alcohol, introduced into the circulation, produces certain determinate states of consciousness; in a word, we observe between the two groups of phenomena relations, whether of invariable coexistence or of invariable succession. It appears to us that this is the only clear and unambiguous way of putting the question with which we are now occupied. Finally, when we strive to get a nearer view of the opposition between the two groups, we find that the higher or psychological group has for its fundamental character consciousness; and thus the antithesis of physical and moral may without too great inaccuracy be regarded as the antithesis of the conscious and the unconscious. If, therefore, we should succeed in showing that this attribute of consciousness which characterizes. one of the groups, and which consequently differentiates the two groups, does not belong to the higher group so essentially or so exclusively as it seems; if we succeed in showing that operations which are considered specially psychological, such as feeling, enjoying, suffering, loving, judging, reasoning, willing can in some cases be either absolutely or relatively unconscious, then the antithesis of physical and moral instead of being absolute would become relative, and the problem would present itself under a new aspect. With a view to resolve it, we will endeavour to penetrate into the mysterious region of the unconscious.