And why?
Because creation is impossible, and, also, because whatever exists must be either a "substance," or an "attribute," or a "mode." What then?
Clearly not an "attribute," for the only attributes known to us are extension and thought, and these attributes are as infinite as "the substance" to which they belong; they must therefore be "modes" or "affections" of that "substance." But in what sense?
In the sense of being created, and therefore dependent, existences, whose nature and origin cannot be conceived of or accounted for without reference to the Being who produced them at first, and still continues to maintain them?
No; for in that sense all Theists admit the derivation and dependence of every finite being; but they must be "modes" or "affections" of the one uncreated essence, mere phenomenal manifestations of it.

The soul, whose essence is thought, is a mere succession of ideas.

The body is a mere "mode" of the Divine "attribute" of extension; and neither the one nor the other can be described as a _distinct being_.

They are affections, and nothing more, of the one infinite "substance." It is important to remark that, according to this theory, _the distinct personality of man_ is excluded, not less than _the distinct personality of God_.

It is not easy, indeed, to explain this part of Spinoza's theory; for he has a subtle disquisition on the relation subsisting between the soul and the body, by means of which he attempts to explain the phenomena of self-consciousness, and to show that individual personality is not necessarily inconsistent with the doctrine which represents man as a mere "mode" of the Divine "substance." But one thing is clear: there is no room in the system of Spinoza for the distinct personality of man, in the ordinary acceptation of that expression.