" I say expressly, that the mind has not an adequate but only a confused knowledge of itself, its own body, and of external bodies, whenever it perceives things after the common order of nature; that is, whenever it is determined from without, namely, by the fortuitous play of circumstance, to regard this or that; not at such times as it is determined from within, that is, by the fact of regarding several things at once, to understand their points of agreement, difference, and contrast. Whenever it is determined in anywise from within, it regards things clearly and distinctly, as I will show below. "

― Baruch Spinoza , Ethics