What is an attribute, as used in Spinoza's Ethics?

Question

In Spinoza's Ethics, the definitions of Part 1. include a supposedly all important term: Attribute, defined by Spinoza in the following:

"IV. By attribute, I mean that which the intellect perceives as constituting the essence of substance."

Reading propositions I through XVI has left me with a good, or at least passable understanding of the concepts of Substance and Modification, but repeatedly propositions such as the following have left me intellectually in the dust.

"PROP. II. Two substances, whose attributes are different, have nothing in common.

PROP. V. There cannot exist in the universe two or more substances having the same nature or attribute.

PROP. IX. The more reality or being a thing has, the greater the number of its attributes (Def. iv.).

My previous conception of attributes was that they were like Platonic Forms, or at least that there was one attribute for every one substance, but it is becoming increasingly clear that this is not at all a workable idea. So, in light of the definition given, could anyone please provide me with a few examples to illustrate what is meant my attribute?

Answer 1

Attributes, for Aristotle, scholastics, Descartes, and Spinoza alike, are the non-accidental qualities/properties expressed in language by predicates, as substances are expressed in it by subjects, to which they are predicated. Taken together, they make a substance what it is, hence they are essential (unlike accidental properties), constitute its essence. Substances that do not share attributes have nothing in common, and the more attributes they have the more "real" (concrete) they are. God, as the ultimate reality, is the "substance of infinite attributes", but according to Spinoza "the human mind has an adequate knowledge of the eternal and infinite essence of God". Here are some examples from Part II of Ethics:

PROP. I. Thought is an attribute of God, or God is a thinking thing.

PROP. II. Extension is an attribute of God, or God is an extended thing.

A somewhat more idiosyncratic use of "attribute" by Spinoza corresponds to what we would call "aspect" or "perspective", in which a substance is unfolded or under which it is considered. In particular, God and Nature are the same substance considered under different attributes (which is perhaps why we have an adequate knowledge of it). Here are some examples, again from Part II:

PROP. V. The actual being of ideas owns God as its cause, only in so far as he is considered as a thinking thing, not in so far as he is unfolded in any other attribute...

Note to PROP. VII. For instance, a circle existing in nature, and the idea of a circle existing, which is also in God, are one and the same thing displayed through different attributes. Thus, whether we conceive nature under the attribute of extension, or under the attribute of thought, or under any other attribute, we shall find the same order, or one and the same chain of causes - that is, the same things following in either case. Thus, whether we conceive nature under the attribute of extension, or under the attribute of thought, or under any other attribute, we shall find the same order, or one and the same chain of causes - that is, the same things following in either case.

Several aspects of interpreting Spinoza's theory of attributes are controversial. For instance, he ultimately concludes, in contradistinction to all his predecessors, that there is but one substance, God=nature, and despite mentioning its infinite attributes names only two of them in Ethics, thought and extension. In the early Short Treatise those are the only two through which God can be known, and omnipotence, eternity, immutability, and infinity are termed "propria", because "they are only Adjectives, which cannot be understood without their Substantives. That is to say, without them God would indeed be no God, but still it is not they that constitute God ; for they reveal nothing of the character of a Substance, through which alone God exists". In Ethics the "propria" disappear altogether, but eternity appears in the oft-mentioned sub specie aeternitatis, "under the species of eternity", in a sense similar to "under the attribute":

Corollary II to PROP. XLIV. It is in the nature of reason to perceive things under a certain form of eternity (sub quâdam æternitatis specie).

SEP has a nice article on Spinoza's Theory of Attributes.

Answer 2

To read a philosopher you must sometimes read the predecessor that that philosopher was responding to. For Spinoza, he was responding to for one, Descartes and his idea of substance/attribute. Descartes uses Aristotle's argument from change to say that the mind is a substance. We all have doubts, imaginations, wills, desires, etc. and they are always in flux. For something to undergo chnage, something must remain underlying that change (some substance is presupposed). What is not in flux however is that they are all mental or "thought-based." So attribute for Descartes was what was empirical derived as what is not changing. He claimed that we are "thinking things". The same argument goes for his famous wax example. All sensible properties of the wax change once heated (smell, taste, etc.) but the wax remains. So the sensible properties are modes or accidents of that thing and that things that remain are extension, ductilibility, and impenetrability. It might be weird for Spinoza to say substance is ductible since in what space is an infinite substance being pulled into? and what other substance is there to penetrate the one and only substance. So he must of kept only extension. it is important to understand that this is an empirical experience (thats why attribute is "perception" of substance), as Kant will later argue that such a thing can be universal or necessary to establish what is called "essence" of a thing. Spinoza is trying to help Descates with the interaction problem (not how two different substances interact but how a purely mental substance doesnt violate the laws of conservation of energy when acting in the world). Spinoza's attribute idea allows for the same substance to have multiple different kind of essences bc they are different ways of talking about the same substance. So not each attribute is conceived logically dependent on each other but in and through the one substance. When we speak about mental activity, we can talk about the will and how we have a desire and mental or thought-based stuff but can never connect it through extended or physical nature. the same for extension; we cannot conceive extension through thought. Otherwise they wouldnt be distinct perceptions. So for Spinoza, though he is a substance monist, is is actually a dualist when it comes to the sensible reality and answers the mind-body problem without an apparent interaction problem.