Extension and motion are the fundamental conceptions in mechanical physics; they represent the truth of the corporeal world. It is thus that ideality comes before the mind of Descartes, and he is far elevated above the reality of the sensuous qualities, although he does not reach so far as to the separation of this ideality. He thus remains at the point of view of mechanism pure and simple. Give me matter (extension) and motion and I will build worlds for you, is what Descartes virtually says.[187] Space and time were hence to him the only determinations of the material universe. In this, then, lies the mechanical fashion of viewing nature, or the natural philosophy of Descartes is seen to be purely mechanical.[188] Hence changes in matter are due merely to motion, so that Descartes traces every relationship to the rest and movement of particles, and all material diversity such as colour, and taste—in short, all bodily qualities and animal phenomena—to mechanism. In living beings processes such as that of digestion are mechanical effects which have as principles, rest and movement. We here see the ground and origin of the mechanical philosophy; but further on we find that this is unsatisfactory, for matter and motion do not suffice to explain life. Yet the great matter in all this is that thought goes forward in its determinations, and that it constitutes from these thought-determinations the truth of nature.
In his consideration of the system of the world and the movement of the heavenly bodies, Descartes has worked out the mechanical view more fully. He thus comes to speak of the earth, the sun, &c., and of his conception of the circling motion of the heavenly bodies in the form of vortices: of metaphysical hypotheses as to how small particles pass into, out of, and through pores and act on one another; and finally to saltpetre and gunpowder.[189]
Universal reflections should have the first claim on our attention; but on the other hand the transition to the determinate is accomplished in a system of Physics which is the result of observations and experiences, and this is done entirely by means of the understanding. Descartes thus mingles many observations with a metaphysic of this nature, and to us the result is hence obscure. In this philosophy the thinking treatment of empiricism is thus predominant, and a similar method has been adopted by philosophers from this time on. To Descartes and others, Philosophy had still the more indefinite significance of arriving at knowledge through thought, reflection, and reasoning. Speculative cognition, the derivation from the Notion, the free independent development of the matter itself, was first introduced by Fichte, and consequently what is now called philosophic knowledge is not yet separated in Descartes from the rest of scientific knowledge. In those times all the knowledge of mankind was called philosophy; in Descartes’ metaphysics we thus saw quite empirical reflection and reasoning from particular grounds, from experiences, facts, phenomena, being brought into play in the naivest manner, and one has no sense of speculation in the matter. The strictly scientific element here really consisted mainly in the method of proof as it has long been made use of in geometry, and in the ordinary method of the formal logical syllogism. Hence it likewise happens that Philosophy, which ought to form a totality of the sciences, begins with logic and metaphysics; the second part is composed of ordinary physics and mathematics, mingled no doubt with metaphysical speculations, and the third part, ethics, deals with the nature of man, his duties, the state, the citizen. And this is the case with Descartes. The first part of the Principia philosophiæ treats De principiis cognitionis humanæ, the second De principiis rerum materialium. This natural philosophy, as a philosophy of extension, is, however, none other than what a quite ordinary physics or mechanics might at that time be, and it is still quite hypothetical; we, on the other hand, accurately distinguish empirical physics and natural philosophy, even though the first likewise pertains to thought.
3. Descartes never reached the third part, the philosophy of Mind, for, while he made a special study of physics, in the region of ethics he published one tract only, De passionibus. In this reference Descartes treats of thought and human freedom. He proves freedom from the fact of the soul thinking that the will is unrestrained, and of that constituting the perfection of mankind. And this is quite true. In respect to the freedom of the will he comes across the difficulty of how to reconcile it with the divine prescience. As free, man might do what is not ordained of God beforehand—this would conflict with the omnipotence and omniscience of God; and if everything is ordained of God, human freedom would thereby be done away with. Yet he does not solve the contradiction contained in these two different aspects without falling into difficulty. But conformably to the method which he adopts, and which we pointed out above (pp. 238, 239), he says: “The human mind is finite, God’s power and predetermination are infinite; we are thus not capable of judging of the relationship in which the freedom of the human soul stands to the omnipotence and omniscience of God—but in self-consciousness we have the certainty of it given us as a fact. And we must hold only to what is certain.”[190] When he proceeds further much appears to him still incapable of explanation; but we see obstinacy and caprice likewise exhibited in his stopping short at the assertion as to the best of his knowledge. The method of knowledge as set forth by Descartes, takes the form of a reasoning of the understanding, and is thus without special interest.
These, then, are the principal points in the Cartesian system. Some particular assertions made by Descartes, which have been specially instrumental in giving him fame, have still to be mentioned—particular forms which have been formerly considered in metaphysics, and likewise by Wolff. For example, in the first place we gather that Descartes regarded animals and other organisms as machines moved by another, and not possessing the principle of the spontaneity of thought within them[191]—a mechanical physiology, a cut and dry thought pertaining to the understanding, which is of no further importance. In the sharp opposition between thought and extension, the former is not considered as sensation, so that the latter can isolate itself. The organic must as body reduce itself to extension; any further development of this last thus only proves its dependence on the first determinations.
In the second place, the relation between soul and body now becomes an important question, that is, the return of the object within itself in such a way that thought posits itself in another, in matter. As to this, many systems are offered to us in metaphysics. One of these is the influxus physicus, that the relation of spirit is of a corporeal nature, that the object is related to mind as bodies are to one another—a conception like this is very crude. How does Descartes understand the unity of soul and body? The former belongs to thought, the latter to extension; and thus because both are substance, neither requires the Notion of the other, and hence soul and body are independent of one another and can exercise no direct influence upon one another. Soul could only influence body in so far as it required the same, and conversely—that is, in so far as they have actual relation to one another. But since each is a totality, neither can bear a real relation to the other. Descartes consistently denied the physical influence of one on the other; that would have signified a mechanical relation between the two. Descartes thus established the intellectual sphere in contradistinction to matter, and on it based the independent subsistence of mind; for in his cogito ‘I’ is at first only certain of itself, since I can abstract from all. Now we find the necessity of a mediator to bring about a union of the abstract and the external and individual. Descartes settles this by placing between the two what constitutes the metaphysical ground of their mutual changes, God. He is the intermediate bond of union, in as far as He affords assistance to the soul in what it cannot through its own freedom accomplish, so that the changes in body and soul may correspond with one another.[192] If I have desires, an intention, these receive corporeal realization; this association of soul and body is, according to Descartes, effected through God. For above (p. 239) we saw that Descartes says of God that He is the Truth of the conception: as long as I think rightly and consistently, something real corresponds to my thought, and the connecting link is God. God is hereby the perfect identity of the two opposites, since He is, as Idea, the unity of Notion and reality. In the Idea of Spinoza this is worked out and developed in its further moments. Descartes’ conclusion is quite correct; in finite things this identity is imperfect. Only the form employed by Descartes is inadequate; for it implies that in the beginning there are two things, thought or soul and body, and that then God appears as a third thing, outside both—that He is not the Notion of unity, nor are the two elements themselves Notion. We must not however forget that Descartes says that both those original elements are created substances. But this expression ‘created’ pertains to the ordinary conception only and is not a determinate thought; it was Spinoza, therefore, who first accomplished this return to thought.
[2. Spinoza.]
The philosophy of Descartes underwent a great variety of unspeculative developments, but in Benedict Spinoza a direct successor to this philosopher may be found, and one who carried on the Cartesian principle to its furthest logical conclusions. For him soul and body, thought and Being, cease to have separate independent existence. The dualism of the Cartesian system Spinoza, as a Jew, altogether set aside. For the profound unity of his philosophy as it found expression in Europe, his manifestation of Spirit as the identity of the finite and the infinite in God, instead of God’s appearing related to these as a Third—all this is an echo from Eastern lands. The Oriental theory of absolute identity was brought by Spinoza much more directly into line, firstly with the current of European thought, and then with the European and Cartesian philosophy, in which it soon found a place.
First of all we must, however, glance at the circumstances of Spinoza’s life. He was by descent a Portuguese Jew, and was born at Amsterdam in the year 1632; the name he received was Baruch, but he altered it to Benedict. In his youth he was instructed by the Rabbis of the synagogue to which he belonged, but he soon fell out with them, their wrath having been kindled by the criticisms which he passed on the fantastic doctrines of the Talmud. He was not, therefore, long in absenting himself from the synagogue, and as the Rabbis were in dread lest his example should have evil consequences, they offered him a yearly allowance of a thousand gulden if he would keep away from the place and hold his tongue. This offer he declined; and the Rabbis thereafter carried their persecution of him to such a pitch that they were even minded to rid themselves of him by assassination. After having made a narrow escape from the dagger, he formally withdrew from the Jewish communion, without, however, going over to the Christian Church. He now applied himself particularly to the Latin language, and made a special study of the Cartesian philosophy. Later on he went to Rhynsburg, near Leyden, and from the year 1664 he lived in retirement, first at Voorburg, a village near the Hague, and then at the Hague itself, highly respected by numerous friends: he gained a livelihood for himself by grinding optical glasses. It was no arbitrary choice that led him to occupy himself with light, for it represents in the material sphere the absolute identity which forms the foundation of the Oriental view of things. Although he had rich friends and mighty protectors, among whom even generals were numbered, he lived in humble poverty, declining the handsome gifts offered to him time after time. Nor would he permit Simon von Vries to make him his heir; he only accepted from him an annual pension of three hundred florins; in the same way he gave up to his sisters his share of their father’s estate. From the Elector Palatine, Carl Ludwig, a man of most noble character and raised above the prejudices of his time, he received the offer of a professor’s chair at Heidelberg, with the assurance that he would have liberty to teach and to write, because “the Prince believed he would not put that liberty to a bad use by interfering with the religion publicly established.” Spinoza (in his published letters) very wisely declined this offer, however, because “he did not know within what limits that philosophic liberty would have to be confined, in order that he might not appear to be interfering with the publicly established religion.” He remained in Holland, a country highly interesting in the history of general culture, as it was the first in Europe to show the example of universal toleration, and afforded to many a place of refuge where they might enjoy liberty of thought; for fierce as was the rage of the theologians there against Bekker, for example (Bruck. Hist. crit. phil. T. IV. P. 2, pp. 719, 720), and furious as were the attacks of Voetius on the Cartesian philosophy, these had not the consequences which they would have had in another land. Spinoza died on the 21st of February, 1677, in the forty-fourth year of his age. The cause of his death was consumption, from which he had long been a sufferer; this was in harmony with his system of philosophy, according to which all particularity and individuality pass away in the one substance. A Protestant divine, Colerus by name, who published a biography of Spinoza, inveighs strongly against him, it is true, but gives nevertheless a most minute and kindly description of his circumstances and surroundings—telling how he left only about two hundred thalers, what debts he had, and so on. A bill included in the inventory, in which the barber requests payment due him by M. Spinoza of blessed memory, scandalizes the parson very much, and regarding it he makes the observation: “Had the barber but known what sort of a creature Spinoza was, he certainly would not have spoken of his blessed memory.” The German translator of this biography writes under the portrait of Spinoza: characterem, reprobationis in vultu gerens, applying this description to a countenance which doubtless expresses the melancholy of a profound thinker, but is otherwise mild and benevolent. The reprobatio is certainly correct; but it is not a reprobation in the passive sense; it is an active disapprobation on Spinoza’s part of the opinions, errors and thoughtless passions of mankind.[193]