thing can exist a single moment without being sustained and preserved by his power. Accordingly, the School is right in saying that the term "substance" does not apply to God and the creatures univocally. Hence, creatures are not substances in the proper sense. Some are substances as compared with others; they are not substances as compared with God, for they depend on him.

Descartes, therefore, understands by relative and finite substance a thing which needs nothing but God in order to exist; by mode, that which cannot exist or be conceived without something else which is its substance; by attribute, the essential quality of the substance, from which we cannot abstract without at the same time destroying the substance itself.

Minds and bodies are (relative) substances. Thought constitutes the attribute, i. e., the essence of mind; 2 extension, the attribute, i. e., the essence of body.

From the fact that extension constitutes the essence of body, it follows: (1) That there can be no extension in the universe without body, i.e., no empty space; nor bodies without extension, i. e., atoms; (2) That the corporeal world is illimitable, since extension cannot be conceived as having limits (here Descartes contradicts Aristotle and agrees with Bruno); (3) That body has, strictly speaking, no centre, that its form is naturally eccentric and its, motion centrifugal; for the centre is a mathematical point, and the mathematical point, inextended.

The properties of extension are divisibility, figurability, and mobility. But divisibility is merely a movement of

1 Principles, I., 51.

2 Id., I., 9: By the word thought I understand everything that so takes place in us that we of ourselves immediately perceive it; hence, not only to understand, to will, to imagine, but even to feel, are the same as to think.

separation and of union. Hence, the properties of exten sion, and consequently of matter, consist in motion.

There is no other motion than motion in extension, local motion or change of place.

Furthermore, motion cannot originate in the bodies themselves: they cannot be said to move themselves, to set themselves in motion and to persist in it of themselves; for bodies are extended, extended only, even in their smallest parts, and absolutely devoid of the inner principle, the centre of action and impulsion which we call soul or ego. They are entirely passive; they do not move themselves at all, but are moved by external causes. We cannot even say that they are heavy, if we understand by weight a tendency of the body to fall towards the centre of the earth, i. e., a kind of spontaneous activity in matter. The material world knows no other law than the law of necessity. The particles of matter, to which the Creator originally imparted rectilinear motion, are distributed in vortices (tourbillons), forming stars, then planets, which are extinguished stars, and finally other heavenly bodies. The science of the world is a problem of mechanics. The material world is a machine, an indefinite - not infinite chain of move-.

ments, the origin of which is in God.1

However, we must not mix theology with our interpretation of nature; and physics should entirely abandon the search for final causes, which has hitherto impeded the progress of this science.2

Minds are diametrically opposed to bodies: i. e., they are essentially active and free; and just as there is nothing inextended in body, mind contains nothing that is not thought, inextended, and immaterial. Body is everything that mind is not; mind is the absolute negation of everything that body is. The two substances entirely exclude each other, they are entirely opposed to each other: body Principles. II.,

2 d., I., 28.

is absolutely soulless; the soul, absolutely immaterial (dualism of substances, dualistic spiritualism).1

Like soul and body, the science of soul and the science of body have nothing in common. Physics should confine itself wholly to mechanical interpretation, while the soul should be explained only in terms of itself.

Although sensation seems to be an action of the body upon the soul, voluntary motion, an action of the soul upon the body, this is not actually the case; for there can be no reciprocal action between substances whose attributes exclude each other. Man is a composite being, a combination of soul and body. The soul derives its sensible ideas from its own nature on occasion of the corresponding excitations; the body, on the other hand, is an automaton, whose movements are occasioned by the volitions of the soul. The body and the soul lead separate lives; the body is subject to necessity, the soul endowed with free-will; being independent of the body, it survives its destruction. The two parts composing the human being are so exclusive as to make a real union between soul and body absolutely impossible. "Those who never philosophize," Descartes' writes to Princess Elizabeth," and employ their senses only, do not doubt that the soul moves the body, and that the body acts upon the soul. But they regard them both as one and the same thing, i. e., they conceive them to be united; for to

1 Meditation, VI. Here we notice a striking difference between Descartes and Leibniz, between dualistic spiritualism and concrete spiritualism. Descartes goes so far as to deny force (tendance) to body; while Leibniz attributes to it (i. e., to the monads constituting it) not only force, but also perception: it contains the idea which it desires to realize, without, however, being conscious of it. The characteristic trait of mind as compared with body is not perception but apperception, not the tendency itself, but the consciousness of the goal aimed at.

2 A Madame Elizabeth, Princesse Palatine (Letter XIX., Vol. III. ed. Garnier).

conceive things as united is to conceive them as one and the same thing." And when she objects that the reciprocal action between soul and body is a self-evident fact, and that it is easier to attribute extension to the soul than to contradict this evidence, Descartes replies: "I pray your highness kindly to attribute matter and extension to the soul, or, in other words, to conceive it as united to the body; and after you have so conceived it and have tested the notion in your own case, it will not be difficult to see that the matter attributed to thought is not thought itself, and that the extension of this matter is quite different from the extension of thought: the former is bound to a certain place from which it wholly excludes the extension of the body, which is not the case with the latter, and your highness will find no trouble in understanding the distinction between body and soul in spite of the fact that your highness has conceived them as united."

The theory, however, does not hinder Descartes from speaking of the reciprocal action between soul and body, as though this action were real and direct. His anthropol ogy, particularly as formulated in the Traité des passions,1 everywhere assumes what his metaphysics denies. In contradiction to the very explicit statements which have just been quoted, Descartes holds that the soul is united to all parts of the body; that it exercises its functions more especially in the pineal gland; that the soul and the body act upon each other through the medium of this gland and the animal spirits. However, he never goes so far as to identify the "two substances." The Traité de l'homme et de la formation du fœtus2 points out the distinction which he draws between them: the body walks, eats, and breathes; the soul enjoys, suffers, desires, hungers and thirsts, loves, hopes, fears; perceives the ideas of sound, light, smell, 1 Amsterdam, 1650.

2 Paris, 1661 (published by Clerselier). In Latin, Amst., 1677, cum notis Lud. de la Forge.

taste, and resistance; wakes, dreams, and faints. But all these phenomena are consequences consequences and not effects of movements caused in the pores of the brain, the seat of the soul, by the entrance and the exit of the animal spirits. Without the body, and particularly without the brain, all these phenomena, as well as the memory in which they are retained, would disappear, and nothing would be left to the soul except the conception of pure ideas of substance, thought, space, and infinity, — ideas which are wholly independent of sensation. Moreover, the ideas which need the cooperation of the senses, and consequently of the brain, are entirely different from the objects which we suppose them to represent. The idea is imaaterial; the object, material; the idea is therefore the opposite of the object, even though it be its faithful image. Our ideas of material qualities no more resemble the ob jects than pain resembles the needle causing it, or the tickling resembles the feather which occasions it.

We see, the founder of French philosophy, though a rationalist and spiritualist in principle, really approximates empiricism and materialism. His animal-machine anticipates the Man a Machine of La Mettrie. Though dogmatic in his belief that extension is a reality, he is the precursor of Locke, Hume, and Kant, in that he makes a clear and absolute distinction between our ideas of material qualities and their external causes.

$54. The Cartesian School 2

The philosophy of Descartes clearly and accurately expressed the ideals of its age: the downfall of traditional

1 Traité du monde ou de la lumière, chap. 1, Paris, 1664 (published by Clerselier).

2 F. Bouillier, Histoire de la philosophie cartésienne; Damiron, Histoire de la philosophie du dix-septième siècle; E. Saisset, Précurseurs et disciples de Descartes, Paris, 1862; [G. Monchamp, Histoire du Cartésianisme en Belgique, Brussels, 1887].