Substance does not affect us by its mere existence, but through an Attribute. By attribute is meant, according to the fourth definition, "that which the understanding perceives of substance as constituting the essence of it" (quod intellectus de substantia percipit, tanquam ejusdem essentiam constituens). The more reality a substance contains, the more attributes it has; consequently infinite substance possesses an infinite number, each of which gives expression to its essence, but of which two only fall within our knowledge. Among the innumerable divine attributes the human mind knows those only which it finds in itself, thought and extension. Although man beholds God only as thinking and extended substance, he yet has a clear and complete; an adequate—idea of God. Since each of the two attributes is conceived without the other, hence in itself (per se), they are distinct from each other realiter, and independent. God is absolutely infinite, the attributes only in their kind (in suo genere).
How can the indeterminate possess properties? Are the attributes merely ascribed to substance by the understanding, or do they possess reality apart from the knowing subject? This question has given rise to much debate. According to Hegel and Ed. Erdmann the attributes are something external to substance, something brought into it by the understanding, forms of knowledge present in the beholder alone; substance itself is neither extended nor cogitative, but merely appears to the understanding under these determinations, without which the latter would be unable to cognize it. This "formalistic" interpretation, which, relying on a passage in a letter to De Vries (Epist. 27), explains the attributes as mere modes of intellectual apprehension, numbers Kuno Fischer among its opponents. As the one party holds to the first half of the definition, the other places the emphasis on the second half ("that which the understanding perceives—as constituting the essence of substance"). The attributes are more than mere modes of representation—they are real properties, which substance possesses even apart from an observer, nay, in which it consists; in Spinoza, moreover, "must be conceived" is the equivalent of "to be." Although this latter "realistic" party undoubtedly has the advantage over the former, which reads into Spinoza a subjectivism foreign to his system, they ought not to forget that the difference in interpretation has for its basis a conflict among the motives which control Spinoza's thinking. The reference of the attributes to the understanding, given in the definition, is not without significance. It sprang from the wish not to mar the indeterminateness of the absolute by the opposition of the attributes, while, on the other hand, an equally pressing need for the conservation of the immanence of substance forbade a bold transfer of the attributes to the observer. The real opinion of Spinoza is neither so clear and free from contradictions, nor so one-sided, as that which his interpreters ascribe to him. Fischer's further interpretation of the attributes of God as his "powers" is tenable, so long as by causa and potentia we understand nothing more than the irresistible, but non-kinetic, force with which an original truth establishes or effects those which follow from it.
As the dualism of extension and thought is reduced from a substantial to an attributive distinction, so individual bodies and minds, motions and thoughts, are degraded a stage further. Individual things lack independence of every sort. The individual is, as a determinate finite thing, burdened with negation and limitation, for every determination includes a negation; that which is truly real in the individual is God. Finite things are modi of the infinite substance, mere states, variable states, of God. By themselves they are nothing, since out of God nothing exists. They possess existence only in so far as they are conceived in their connection with the infinite, that is, as transitory forms of the unchangeable substance. They are not in themselves, but in another, in God, and are conceived only in God. They are mere affections of the divine attributes, and must be considered as such.
To the two attributes correspond two classes of modes. The most important modifications of extension are rest and motion. Among the modes of thought are understanding and will. These belong in the sphere of determinate and transitory being and do not hold of the natura naturans: God is exalted above all modality, above will and understanding, as above motion and rest. We must not assert of the natura naturata (the world as the sum of all modes), as of the natura naturans, that its essence involves existence (I. prop. 24): we can conceive finite things as non-existent, as well as existent (Epist. 29). This constitutes their "contingency," which must by no means be interpreted as lawlessness. On the contrary, all that takes place in the world is most rigorously determined; every individual, finite, determinate thing and event is determined to its existence and action by another similarly finite and determinate thing or event, and this cause is, in turn, determined in its existence and action by a further finite mode, and so on to infinity (I. prop. 28). Because of this endlessness in the series there is no first or ultimate cause in the phenomenal world; all finite causes are second causes; the primary cause lies within the sphere of the infinite and is God himself. The modes are all subject to the constraint of an unbroken and endless nexus of efficient causes, which leaves room neither for chance, nor choice, nor ends. Nothing can be or happen otherwise than as it is and happens (I. prop. 29, 33).
The causal chain appears in two forms: a mode of extension has its producing ground in a second mode of extension; a mode of thought can be caused only by another mode of thought—each individual thing is determined by one of its own kind. The two series proceed side by side, without a member of either ever being able to interfere in the other or to effect anything in it—a motion can never produce anything but other motions, an idea can result only in other ideas; the body can never determine the mind to an idea, nor the soul the body to a movement. Since, however, extension and thought are not two substances, but attributes of one substance, this apparently double causal nexus of two series proceeding in exact correspondence is, in reality, but a single one. (III. prop. 2, schol.) viewed from different sides. That which represents a chain of motions when seen from the side of extension, bears the aspect of a series of ideas from the side of thought. Modus extensionis et idea illius modi una cademque est res, sed duobus modis expressa (II. prop. 7, schol.; cf. III. prop. 2, schol.). The soul is nothing but the idea of an actual body, body or motion nothing but the object or event in the sphere of extended actuality corresponding to an idea. No idea exists without something corporeal corresponding to it, no body, without at the same time existing as idea, or being conceived; in other words, everything is both body and spirit, all things are animated (II. prop. 13, schol.). Thus the famous proposition results; Ordo et connexio idearum idem est ac ordo et connexio rerum (sive corporum; II. prop. 7), and in application to man, "the order of the actions and passions of our body is simultaneous in nature with the order of the actions and passions of the mind" (III. prop. 2, schol.).
The attempt to solve the problem of the relation between the material and the mental worlds by asserting their thoroughgoing correspondence and substantial identity, was philosophically justifiable and important, though many evident objections obtrude themselves upon us. The required assumption, that there is a mental event corresponding to every bodily one, and vice versa, meets with involuntary and easily supported opposition, which Spinoza did nothing to remove. Similarly he omitted to explain how body is related to motion, mind to ideas, and both to actuality. The ascription of a materialistic tendency to Spinoza is not without foundation. Corporeality and reality appear well-nigh identical for him,—the expressions corpora and res are used synonymously,—so that there remains for minds and ideas only an existence as reflections of the real in the sphere of [an] ideality (whose degree of actuality it is difficult to determine). Moreover, individualistic impulses have been pointed out, which, in part, conflict with the monism which he consciously follows, and, in part, subserve its interests. An example of this is given in the relation of mind and idea: Spinoza treats the soul as a sum of ideas, as consisting in them. An (at least apparently substantial) bond among ideas, an ego, which possesses them, does not exist for him: the Cartesian cogito has become an impersonal cogitatur or a Deus cogitat. In order to the unique substantiality of the infinite, the substantiality of individual spirits must disappear. That which argues for the latter is their I-ness (Ichheit), the unity of self-consciousness; it is destroyed, if the mind is a congeries of ideas, a composite of them. Thus in order to relieve itself from the self-dependence of the individual mind, monism allies itself with a spiritual atomism, the most extreme which can be conceived. The mind is resolved into a mass of individual ideas.
Mention may be made in passing, also, of a strange conception, which is somewhat out of harmony with the rest of the system, and of which, moreover, little use is made. This is the conception of infinite modes. As such are cited, facies totius mundi, motus et quies, intellectus absolute infinitus. Kuno Fischer's interpretation of this difficult conception may be accepted. It denotes, according to him, the connected sum of the modes, the itself non-finite sum total of the finite—the universe meaning the totality of individual things in general (without reference to their nature as extended or cogitative); rest and motion, the totality of material being; the absolutely infinite understanding, the totality of spiritual being or the ideas. Individual spirits together constitute, as it were, the infinite intellect; our mind is a part of the divine understanding, yet not in such a sense that the whole consists of the parts, but that the part exists only through the whole. When we say, the human mind perceives this or that, it is equivalent to saying that God—not in so far as he is infinite, but as he expresses himself in this human mind and constitutes its essence—has this or that idea (II. prop. II, coroll).
The discussion of these three fundamental concepts exhausts all the chief points in Spinoza's doctrine of God. Passing over his doctrine of body (II. between prop. 13 and prop. 14) we turn at once to his discussion of mind and man.
%(b) Anthropology: Cognition and the Passions.%—Each thing is at once mind and body, representation and that which is represented, idea and ideate (object). Body and soul are the same being, only considered under different attributes. The human mind is the idea of the human body; it cognizes itself in perceiving the affections of its body; it represents all that takes place in the body, though not all adequately. As man's body is composed of very many bodies, so his soul is composed of very many ideas. To judge of the relation of the human mind to the mind of lower beings, we must consider the superiority of man's body to other bodies; the more complex a body is, and the greater the variety of the affections of which it is capable, the better and more adapted for adequate cognition, the accompanying mind.—A result of the identity of soul and body is that the acts of our will are not free (Epist. 62): they are, in fact, determinations of our body, only considered under the attribute of thought, and no more free than this from the constraint of the causal law (III. prop. 2, schol.).—Since the mind does nothing without at the same time knowing that it does it—since, in other words, its activity is a conscious activity, it is not merely idea corporis humani, but also idea ideae corporis or idea mentis.
All adherents of the Eleatic separation of the one pure being from the manifold and changing world of appearance are compelled to make a like distinction between two kinds and two organs of knowledge. The representation of the empirical manifold of separately existing individual things, together with the organ thereof, Spinoza terms imaginatio; the faculty of cognizing the true reality, the one, all-embracing substance, he calls intellectus. Imaginatio (imagination, sensuous representation) is the faculty of inadequate, confused ideas, among which are included abstract conceptions, as well as sensations and memory-images. The objects of perception are the affections of our body; and our perceptions, therefore, are not clear and distinct, because we are not completely acquainted with their causes. In the merely perceptual stage, the mind gains only a confused and mutilated idea of external objects, of the body, and of itself; it is unable to separate that in the perception (e.g., heat) which is due to the external body from that which is due to its own body. An inadequate idea, however, is not in itself an error; it becomes such only when, unconscious of its defectiveness, we take it for complete and true. Prominent examples of erroneous ideas are furnished by general concepts, by the idea of ends, and the idea of the freedom of the will. The more general and abstract an idea, the more inadequate and indistinct it becomes; and this shows the lack of value in generic concepts, which are formed by the omission of differences. All cognition which is carried on by universals and their symbols, words, yields opinion and imagination merely instead of truth. Quite as valueless and harmful is the idea of ends, with its accompaniments. We think that nature has typical forms hovering before it, which it is seeking to actualize in things; when this intention is apparently fulfilled we speak of things as perfect and beautiful; when it fails, of imperfect and ugly things. Such concepts of value belong in the sphere of fictions. The same is true of the idea of the freedom of the will, which depends on our ignorance of that which constrains us. Apart from the consideration that "the will," the general conception of which comes under the rubric of unreal abstractions, is in fact merely the sum of the particular volitions, the illusion of freedom, e.g., that we will and act without a cause, arises from the fact that we are conscious of our action (and also of its proximate motives), but not of its (remoter) determining causes. Thus the thirsty child believes it desires its milk of its own free will, and the timid one, that it freely chooses to run away (Ethica, III. prop. 2, schol.; I. app.) If the falling stone were conscious, it would, likewise, consider itself free, and its fall the result of an undetermined decision.