Whatsoever can be perceived by the infinite intellect as constituting the essence of substance, belongs altogether only to one substance: consequently, substance thinking and substance extended are one and the same substance, comprehended now through one attribute, now through another. So, also, a mode of extension and the idea of that mode are one and the same thing, though expressed in two ways. This truth seems to have been dimly recognized by those Jews who maintained that God, God's intellect, and the things understood by God are identical. ...Thus, whether we conceive of nature 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 follow in either case. ...Wherefore of things as they are of themselves, God is really the cause, inasmuch as he consists of infinite attributes.
Baruch Spinoza, in Ethics Geometrically Demonstrated (1677), Prop. 7: Note