Selection from – Ethics – Part I. Definitions III, IV and VI (Page 1)

Spinoza's Words: (substance and God defined)

Opening the pages of Ethics we immediately are faced with definitions.

III. By substance, I mean that which is in itself, and is conceived through itself: in other words, that of which a conception can be formed independently of any other conception.

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

VI. By God I mean a being absolutely infinite—that is, a substance consisting in infinite attributes, of which each expresses eternal and infinite essentiality


As we shall see, Spinoza's conception of God is not the usual one. He identifies the word as identical to the totality of the laws, processes and products of nature. For Spinoza God and Nature are identical. He uses the Latin phrase (Deus sive Natura) (God or Nature).

Exercising an author's prerogative I will henceforth change the translated word God to (Deus sive Natura), when it refers to Spinoza's concept. I hope that this will not upset the reader. I believe it will be helpful because the word God carries such a strong image that trying to remember Spinoza's revision when the word appears in the text often breaks the thought and when the revision is not brought to mind it does violence to Spinoza's meaning.


We must not let the language at the beginning of this work upset us or deter us from the journey ahead. It is well worth riding over the shoals to get to the broad waters that lie ahead. Spinoza worked with the tools (language) at hand. There is a long tradition in philosophy, dating back to Aristotle, of the use of the concept of "substance" when speaking of the basic things.

Spinoza is a monist, that is, he believes that reality is basically one thing, in contrast to Descartes' dualism. He uses the word substance as that which lays under everything, that which supports all, the very structure of existence. We approach his meaning of the word when we speak of the substance of someone's remarks.

He maintains that (Deus sive Natura) is infinite. (The totality of all-that-is has no boundaries.) By attribute he means ways of being that we can perceive. We know of only two attributes. They are mental phenomena (mind) and physical things (extension in space). When he says that (Deus sive Natura) has infinite attributes he is making a logical conjecture. If something is truly infinite there are surely infinite ways of perceiving it.

We need not agree exactly with these definitions but they will help us as we build an understanding of Spinoza's system. Below the propositions he has written proofs using the definitions and previous propositions in a carefully point-by-point way, finally ending with QED. Sometimes Spinoza extends the proofs by adding explanatory Notes or/and Corollaries. It is all constructed very logically and Spinoza often shows his confidence in his method by including phases like "It is obviously clear that...." "It must, then, necessarily be admitted that...," "It is thus evident that...,"As I have thus shown, more clearly than the sun at noonday, that..."

It is to noted that by equating (Deus sive Natura) with substance and defining that entity as infinite and necessary for all that is, he has equated a power that makes all with the natural world and justifies our use of the term (Deus sive Natura). In all that follows (Deus sive Natura) means Natural Processes plus Divine Power as one entity.