The Works of Benedictus de Spinoza

...the absolute is within the human mind, let it be deduced, they have instructed more correctly and more happily. Cf. Rehberg, The Relation of Metaphysics to Religion (Berlin 1787, 8vo). Those who begin philosophizing from the mind itself are permitted to focus their attention on that which is within us, or rather, on what we ourselves are, and to observe it from up close, so to speak, from within. From a certainty, one must then proceed further by attempting to lay firm foundations with cautious reasoning. For nothing at all can be more certain to us who think than our very own Being. Nor can any other measure of certainty be conceived as manageable for us humans than this: whether something exists within our Being, and whether it could be denied only if this were denied, such that those things which stand or fall with our necessary Being deserve to be called true, while those which rely only on accidents in this Being of ours and are equal to them are merely appearances of truth. Conversely, if they begin the journey of philosophizing from the Infinite, they cannot deny that they are proceeding from a mystery that is for the most part inscrutable, as Spinoza himself understands God to be a substance consisting of infinite attributes (Ethics, Def. VI), of which he thought he had knowledge of only two, namely, that it is thinking and extended (Ethics, P. II, prop. 1, 2). And these very two attributes, through which he professed to have as clear an idea of God as of a triangle (Epistle LX, p. 659, Vol. I)—whence, finally, could he have had true knowledge of them? Had he not considered his own mind before all else, he would have had neither the concept of thinking nor...