We thus, by help of the universal, acquire a theoretical knowledge of particulars, but we do not know them by the special observation properly belonging to each particular case: so that we may err in respect to them without any positive contrariety between our cognition and our error; since what we know is the universal, while what we err in is the particular. We may even know that A is predicable of all B, and that B is predicable of all C; and yet we may believe that A is not predicable of C. We may know that every mule is barren, and that the animal before us is a mule, yet still we may believe her to be in foal; for perhaps we may never have combined in our minds the particular case along with the universal proposition.[41] _A fortiori_, therefore, we may make the like mistake, if we know the universal only, and do not know the particular. And this is perfectly possible. For take any one of the visible particular instances, even one which we have already inspected, so soon as it is out of sight we do not know it by actual and present cognition; we only know it, partly from the remembrance of past special inspection, partly from the universal under which it falls.[42] We may know in one, or other, or all, of these three distinct ways: either by the universal; or specially (as remembered): or by combination of both--actual and present cognition, that is, by the application of a foreknown generality to a case submitted to our senses. And as we may know in each of these three ways, so we may also err or be deceived in each of the same three ways.[43] It is therefore quite possible that we may know, and that we may err or be deceived about the same thing, and that, too, without any contrariety. This is what happens when we know both the two premisses of the syllogism, but have never reflected on them before, nor brought them into conjunction in our minds. When we believe that the mule before us is in foal, we are destitute of the actual knowledge; yet our erroneous belief is not for that reason contrary to knowledge; for an erroneous belief, contrary to the universal proposition, must be represented by a counter-syllogism.[44] [Footnote 41: Ibid. II. xxi. p. 67, a. 36: [Greek: ou) ga\r e)pi/statai o(/ti to\ A tô=| G, _mê\ suntheôrô=n_ to\ kath' e(ka/teron.]] [Footnote 42: Analyt. Prior. II. xxi. p. 67, a. 39: [Greek: ou)de\n ga\r tô=n ai)sthêtô=n e)/xô tê=s ai)sthê/seôs geno/menon i)/smen, ou)/d' a)\n ê)|sthême/noi tugcha/nômen, ei) mê\ ô(s tô=| katho/lou kai\ tô=| e)/chein tê\n oi)kei/an e)pistê/mên, a)ll' _ou)ch ô(s tô=| e)nergei=n_.]