28. The Stoic theory raises numberless further objections; but we halt here lest we ourselves incur ridicule in combating so evident an absurdity. It suffices if we have demonstrated that these philosophers mistake non-essence for absolute essence; (putting the cart before the horse), they assign the First rank to what should occupy the last. The cause of their error is that they have chosen sensation as guide, and have consulted nothing else in determining both their principles, and consequences. Being persuaded that the bodies are genuine essences,[292] and refusing to believe that they transform themselves into each other, they believed that what subsisted in them (in the midst of their changes) is the real essence, just as one might imagine that place, because it is indestructible, is more essential than (metabolic) bodies. Although in the system of the Stoics place remain unaltered, these philosophers should not have regarded as essence that which subsists in any manner soever; they should, first, have considered what are the characteristics necessarily possessed by essence, the presence of which (characteristics) makes it subsist without undergoing any alteration. Let us indeed suppose that a shadow would continuously subsist by following something which changes continuously; the shadow, however, would not be no more real than the object it follows. The sense-world, taken together with its multiple objects, is more of an essence than the things it contains, merely because it is their totality. Now if this subject, taken in its totality, be non-essence, how could it be a subject? The most surprising thing, however, is that the (Stoics), in all things following the testimony of sensation, should not also have affirmed that essence can be perceived by sensation; for, to matter, they do not attribute impenetrability, because it is a quality (and because, according to them, matter has no quality). If they insist that matter is perceived by intelligence,[293] it could only be an irrational intelligence which would consider itself inferior to matter, and attribute to it, rather than to itself, the privilege of constituting genuine essence. Since in their system intelligence is non-essence, how could any credibility attach to that intelligence when it speaks of things superior to it, and with which it possesses no affinity? But we have said enough of the nature of these subjects, elsewhere.[294] 2. QUALITY. QUALITIES ARE INCORPOREAL.