Baruch or Benedict Spinoza was born at Amsterdam, Nov. 24, 1632. His parents were Jews of Portuguese descent, and being merchants of opulence, they gave him a finished education. He studied with great diligence the Bible and the Talmud, but soon exchanged the pursuit of theology for the study of physics and the works of Descartes. He early became dissatisfied with Judaism, and presently came to an open rupture with it, though without going over formally to Christianity. In order to escape the persecutions of the Jews, who had excommunicated him, and who even went so far as to make an attempt upon his life, he left Amsterdam and betook himself to Rhynsberg, near Leyden. He finally settled down at the Hague, where he spent his life in the greatest seclusion, devoted wholly to scientific pursuits. He supported himself by grinding optic glasses, which his friends sold for him. The Elector Palatine, Charles Louis, offered him a Professorship of Philosophy at Heidelberg, with the full permission to teach as he chose, but Spinoza declined the post. Naturally of a weak constitution, which consumption had for many years been undermining, Spinoza died at the age of 44, on the 21st of February, 1677. In his life there was mirrored the unclouded clearness and exalted serenity of the perfected sage. Abstemious in his habits, satisfied with little, the master of his passions, never intemperately sad nor joyous, gentle and benevolent, with a character of singular excellence and purity, he faithfully illustrated in his life, the doctrines of his philosophy. His chief work, the Ethica, appeared the year of his death. His design was probably to have published it during his life, but the odious report that he was an atheist restrained him. The friend he most trusted, Louis Mayer, a physician, attended to its publication after the author’s death and according to his will.

The system of Spinoza rests upon three fundamental conceptions, from which all the rest may be derived with mathematical necessity. These conceptions are that of substance, of attribute, and of mode.

1. Spinoza starts from the Cartesian conception of substance: substance is that which needs nothing other for its existence. But with such a conception there can exist only one single substance. A number of substances like that of Descartes is necessarily a contradiction. There can be nothing which has a substantial being besides the one substance of all things. This one substance Spinoza calls God. Of course, with such a view, the Christian idea of God, the notion of a spiritual and personal being, must be laid aside. Spinoza expressly declares, that his notion of God is entirely different from that of the Christian; he denied that understanding and will could be predicated of God; he ridiculed those who supposed that God worked for an end, and even scorned the view which regarded the world as a product of the Divine willing or thinking. God is, with him, only substance, and nothing more. The propositions that there is only one God, and that the substance of all things is only one, are with him identical.

What now peculiarly is this substance? What is positive being? This question it is very difficult to answer directly from the standpoint of Spinoza, partly because a definition, according to him, must contain (i. e. must be genetically) the immediate cause of that which is to be explained, but substance is uncreated and can have no cause besides itself; but prominently because Spinoza held that every determination is a negation, since it must indicate a want of existence, a relative not-being. (Omnis determinatio est negatio is an expression which, though he uses it only occasionally, expresses the fundamental idea of his whole system.) Hence, by setting up any positive determinations of being, we only take away from substance its infinity and make it finite. When we therefore affirm any thing concerning it, we can only speak negatively, e. g. that it has no foreign cause, that it has no plurality, that it cannot be divided, etc. It is even reluctantly that Spinoza declares concerning it that it is one, for this predicate might readily be taken numerically, as implying that others, the many, stood over against it. Thus there can remain only such positive affirmations respecting it as express its absolute reference to itself. In this sense Spinoza says that substance is the cause of itself, i. e. its being concludes existence in itself. When Spinoza calls it eternal, it is only another expression for the same thought; for by eternity he understands existence itself, so far as it is conceived to follow from the definition of the thing, in a sense similar to that in which geometricians speak of the eternal properties of figures. Still farther he calls substance infinite, because the conception of infinity expressed to him the conception of true being, the absolute affirmation of existence. So also the expression, God is free, affirms nothing more than those already mentioned, viz., negatively, that every foreign restraint is excluded from him, and positively, that God is in harmony with himself, that his being corresponds to the laws of his essence.

The comprehensive statement for the above is, that there is only one infinite substance that excludes from itself all determination and negation, and is named God, or nature.

2. Besides the infinite substance or God, Descartes had assumed two other substances created by God, viz., mind (thought), and matter (extension). These two Spinoza considers in the light of attributes, though, like Descartes, he receives them empirically. What, now, is the relation of these attributes to the infinite substance? This is the severe question, the tendon-Achilles of Spinoza’s system. They cannot be essential forms in which the substance may manifest itself or appear, for this would make them determine the essence of the substance, which would contradict its conception as already given. Substance, as such, is neither understanding nor extension. If, then, the two attributes do not flow out of the essence of the substance, and do not constitute the substance, there remains only one other supposition, viz., that they are externally attached to the substance; and this is, in fact, Spinoza’s view. Attribute, according to him, is that which the understanding perceives in the substance as constituting its essence. But understanding, as Spinoza expressly says, does not belong to substance as such. Attributes, therefore, are those determinations which express the essence of the substance only for the perceiving understanding; since they express the essence of the substance in a determinate way, while substance itself has no determinate way of being, they can only fall outside the substance, viz., in the reflective understanding. To the substance itself it is indifferent whether the understanding contemplate it under these two attributes or not; the substance in itself has an infinity of attributes, i. e. every possible attribute which is not a limitation, may be predicated of it; it is only the human understanding which attaches these two attributes to the substance, and it affixes no more than these, because, among all the conceptions it can form, these alone are actually positive, or express a reality. God, or the substance, is therefore thinking, in so far as the understanding contemplates him under the attribute of thought, and is extended in so far as the understanding contemplates him under the attribute of extension. It is, says Spinoza—using a figure to express this relation of substance to attribute—it is, like a surface reflecting the light, which (objectively taken) may be hot, though, in reference to the man looking upon it, it is white. More accurately substance is a surface, standing opposite to a beholder who can see only through yellow and blue glasses; to whom, therefore, the surface must appear either yellow or blue, though it is neither the one nor the other.

In relation to substance, therefore, the attributes must be apprehended as entirely independent: they must be conceived through themselves: their conception is not dependent upon that of substance. This is necessarily true; for since the substance can have no determinateness, then the attribute which is its determinate being, cannot be explained from the substance, but only through itself. Only by apprehending the attribute independently can the unity of the substance be maintained.

In relation to each other, the attributes are to be taken as opposites strictly and determinately diverse. Between the bodily and the ideal world there is no reciprocal influence nor interaction: a body can only spring from a body, and an idea can only have an idea for its source. Hence, therefore, neither the mind can work upon the body nor the body upon the mind. Nevertheless there exists between the two worlds a perfect harmony and an entire parallelism. It is one and the same substance which is conceived under each of the two attributes, and under which one of the two we may contemplate it is indifferent to the substance itself, for each mode of contemplation is equally correct. From this follows at once the proposition of Spinoza, that the connection of ideas and of things is the same. Hence the solution to the problem of the relation of body and soul, so difficult to find from the Cartesian standpoint, is readily seen from that of Spinoza. Body and soul are one and the same thing, only viewed under different attributes. Mind is nothing but the idea of body, i. e. it is the same thing as body, only that it is viewed under the attribute of thought. In the same way is explained the apparent but not real influence of the body upon the mind, and the mind upon the body. That which, in one point of view is bodily motion, in another is an act of thought. In short, the most perfect parallelism reigns between the world of bodily things and that of ideas.

3. Individual beings, which considered under the attribute of thought are ideas, and under the attribute of extension are bodies, Spinoza comprehends under the conception of accidence, or, as he calls it, mode. By modes we are therefore to understand the changing forms of substance. The modes stand related to the substance as the rippling waves of the sea to the water of the sea, as forms constantly disappearing and never having a real being. In fact this example goes too far, for the waves of the sea are at least a part of the water of the sea, while the modes, instead of being parts of the substance, are essentially nothing and without being. The finite has no existence as finite; only the infinite substance has actual existence. Substance, therefore, could not be regarded more falsely than if it should be viewed as made up of modes. That would be, Spinoza remarks, as if one should say that the line is made up out of points. It is just as false to affirm that Spinoza identifies God and the world. He identifies them so little that he would rather say that the world, as world, i. e. as an aggregate of individuals, does not at all exist; we might rather say with Hegel that he denies the world (his system is an acosmism), than with Bayle, that he makes every thing God, or that he ascribes divinity to every thing.

Whence do finite things or individuals arise, if they can have no existence by the side of substance? They are only the product of our deceptive apprehension. There are two chief ways of knowledge—the intuitive, through the reason, and the imaginative. To the latter belong the knowledge of experience, and all that is abstract, superficial, and confused; to the former, the collection of all fitting (adequate) ideas. It is only the fault of the imagination that we should look upon the world as a manifoldness of individuals; the manifoldness is only a form of representation. The imagination isolates and individualizes what the reason sees together in its unity. Hence it is only as considered through the imagination (experience or opinion) that modes are things; the reason looks upon them as necessary, or, what is the same thing, as eternal.

Such are the fundamental thoughts and features of Spinoza’s system. His practical philosophy yet remains to be characterized and in a few words. Its chief propositions follow necessarily from the metaphysical grounds already cited. First, it follows from these, that what is called free will cannot be admitted. For since man is only a mode, he, like every other mode, stands in an endless series of conditioning causes, and no free will can therefore be predicated of him. The will must thus, like the body (and the resolution of the will is only a modification of the body), be determined by something other than itself. Men regard themselves as free only because they are conscious of their actions and not of the determining causes. Just so the notions which one commonly connects with the words good and evil, rest on an error as follows at once from the conception of the absolute divine causality. Good and evil are not something actually in the things themselves, but only express relative conceptions which we have formed from a comparison of things with one another. Thus, by observing certain things we form a certain universal conception, which we thereupon treat as though it were the rule for the being and acting of all individuals, and if any individual varies from this conception we fancy that it does not correspond to its nature, and is incomplete. Evil or sin is therefore only something relative, for nothing happens against God’s will. It is only a simple negation or deprivation, which only seems to be a reality in our representation. With God there is no idea of the evil. What is therefore good and what evil? That is good which is useful to us, and that evil which hinders us from partaking of a good. That, moreover, is useful to us which brings us to a greater reality, which preserves and exalts our being. But our true being is knowledge, and hence that only is useful to us which aids us in knowing; the highest good is the knowledge of God; the highest virtue of the mind is to know and love God. From the knowledge of God we gain the highest gladness and joy of the mind, the highest blessedness. Blessedness, hence, is not the reward of virtue, but virtue itself.

The grand feature of Spinoza’s philosophy is that it buries every thing individual and particular, as a finite, in the abyss of the divine substance. With its view unalterably fixed upon the eternal one, it loses sight of every thing which seems actual in the ordinary notions of men. But its defect consists in its inability to transform this negative abyss of substance into the positive ground of all-being and becoming. The substance of Spinoza, has been justly compared to the lair of a lion, which many footsteps enter, but from which none emerge. The existence of the phenomenal world, though it be only the apparent and deceptive reality of the finite, Spinoza does not explain. With his abstract conception of substance he cannot explain it. And yet the means to help him out of the difficulty lay near at hand. He failed to apply universally his fundamental principle that all determination is negation; he applied it only to the finite, but the abstract infinite, in so far as it stands over against the finite, is also a determinate; this infinite must be denied by its negation, which is the case when a finite world is posited. Jacob Boehme rightly apprehended this, when he affirmed, that without a self-duplication, without an ingress into the limited, the finite, the original ground of things is an empty nothing (cf. § XXIII. 8). So the original ground of Spinoza is a nothing, a purely indeterminate, because with him substance was only a principle of unity and not also a principle of distinction, because its attributes, instead of being an expression of an actual difference and a positive distinction to itself, are rather wholly indifferent to itself. The system of Spinoza is the most abstract Monotheism that can be thought. It is not accidental that its author, a Jew, should have brought out again this view of the world, this view of absolute identity, for it is in a certain degree with him only a consequence of his national religion—an echo of the Orient.