[Footnote 150: Plato, Republic, v. p. 476 D. [Greek: Ou)kou=n tou/tou me\n tê\n dia/noian ô(s gignô/skontos _gnô/mên_ a)\n o)rthô=s phai=men ei)=nai, tou= de\ _do/xan_, ô(s doxa/zontos.]] [Side-note: Ens alone can be known--Non-Ens is unknowable. That which is midway between Ens and Non-Ens (particulars) is matter only of opinion. Ordinary men attain nothing beyond opinion.] This latter, the unphilosophical man, will not admit what we say. Accordingly, we must prove it to him. You cannot know without knowing Something: that is, Some Ens: for Non-Ens cannot be known. That which is completely and absolutely Ens, is completely and absolutely cognizable: that which is Non-Ens and nowhere, is in every way uncognizable. If then there be anything which is at once Ens and Non-Ens, it will lie midway between these two: it will be something neither absolutely and completely cognizable, nor absolutely and completely uncognizable: it belongs to something between ignorance and science. Now science or knowledge is one thing, its object is, complete Ens. Opinion is another thing, its object also is different. Knowing and Opining belong, like Sight and Hearing, to the class of Entia called Powers or Faculties, which we and others possess, and by means of which--that is, by means of one or other of them--we accomplish everything that we do accomplish. Now no one of these powers or faculties has either colour or figure, whereby it may be recognised or distinguished from others. Each is known and distinguished, not by what it is in itself, but by what it accomplishes, and by the object to which it has special relation. That which has the same object and accomplishes the same result, I call the same power or faculty: that which has a different object, and accomplishes a different result, I call a different power or faculty. Now Knowing, Cognition, Science, is one of our faculties or powers, and the strongest of all: Opining is another, and a different one. A marked distinction between the two is, that Knowing or Cognition is infallible--Opining is fallible. Since Cognition is one power or faculty, and Opining another--the object of one must be different from the object of the other. But the object of Cognition is, the Complete Ens: the object of Opining must therefore be, not the Complete Ens, but something different from it. What then is the object of Opining? It is not Complete Ens, but it is still Something. It is not Non-Ens, or Nothing; for Non-Ens or Nothing is not thinkable or opinable: you cannot think or opine, and yet think or opine nothing. Whoever opines or thinks, must opine or think something. Ens is the object of Cognition, Non-Ens is the object of non-Cognition or Ignorance: Opination or Opinion is midway between Cognition and Ignorance, darker than the former, but clearer than the latter. The object of opination is therefore something midway between Ens and Non-Ens.