De Piscibus Libri V et De Cetis Liber Unus

human mind. See Rehberg, The Relation of Metaphysics to Religion (Berlin 1787, 8vo). For those beginning to philosophize from the mind itself, it is permitted to fix attention upon that which is within us, or rather upon what we ourselves are, and to behold it from close range, as it were, intrinsically. Then, one must proceed from the certain, striving to build firm foundations with cautious reasoning. For nothing at all can be more certain to us who think than our own Esse Being. Nor can any other measure of certainty be thought of, tractable to us humans, than this: whether something exists within our Esse, and whether it could be denied only if this were denied, in such a way that those things deserve to be called true which stand or fall with our necessary Esse, whereas those things are merely probable which rest only on accidents within this Esse of ours and are equal to them. Conversely, if they institute the journey of philosophizing from the Infinite, they cannot deny that they are proceeding from a mystery that is, for the greatest part, inscrutable—just as Spinoza himself understands God as a substance consisting of infinite attributes (Eth. Def. VII), of which he thought he had knowledge of only two, namely, that it is thinking and extended (Eth. 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 (Epist. LX, p. 659, Vol. I), from where could he finally have had them truly known? Had he not considered his own mind before all else, he would not have attained the notion of thinking or