So far they proceed under the direction of reason, of necessary thinking, and so far they are truly philosophical. But, on the other hand, they are truly unphilosophical in their details, or in their attempts to show what the universal in all things is. The true universal is certainly not water; it is certainly not formless or unlimited matter; it is certainly not air: for though we are under the necessity of thinking some universal in all things, we are not under the necessity of thinking this as water, or as formless matter, or as air; therefore these elements are not forced on our acceptance by any necessity of thought; therefore they are only relatively, and not absolutely, true, they are only truths for some and not truths for all intelligence: they are at the utmost merely truths for the senses and the understanding, not for the reason; they are merely disguised sensibles, and, as such, we cannot accept them as the veritable universal of which philosophy is in quest.