themselves, and wearying or bothering their hearers: and those who make money by such private dialogues. This last sort of wrangler is the Sophist.[22] [Footnote 19: Plato, Sophist. p. 219 E.] [Footnote 20: Plato, Sophist. p. 225 C. [Greek: _Xe/nos_.--Tou= de\ a)ntilogikou=, to\ me\n o(/son peri\ ta\ xumbolai=a a)mphisbêtei=tai me/n, ei)kê= de\ kai\ a)technô=s peri\ au)to\ pra/ttetai, tau=ta _thete/on me\n ei)=dos_, e)pei/per au)to\ die/gnôken ô(s e(/teron o)\n o( lo/gos; a)ta\r e)pônumi/as ou)/th' u(po\ tô=n e)/mprosthen e)/tuchen, ou)/te nu=n u(ph' ê(mô=n tuchei=n a)/xion. _Theaitêt_.--A)lêthê=; kata\ _smikra\_ ga\r li/an kai\ _pantodapa\_ diê/|rêtai.] These words illustrate Plato's view of an [Greek: ei)=dos] or species. Any distinguishable attributes, however petty, and however multifarious, might be taken to form a species upon; but if they were petty and multifarious, there was no advantage in bestowing a specific name.] [Footnote 21: Plato, Sophist. p. 225 C. [Greek: to\ de/ ge e)/ntechnon, kai\ peri\ _dikai/ôn au)tô=n_ kai\ a)di/kôn kai\ peri\ tô=n _a)/llôn o(/lôs_ a)mphisbêtou=n, a)=r' ou)k e)ristiko\n au)= le/gein ei)thi/smetha?]] [Footnote 22: Plato, Sophist. p. 225 E.] [Side-note: The Sophist is traced down, from the genus of separating or discriminating art.] There is yet another road of class-distribution which will bring us down to the Sophist. A great number of common arts (carding wool, straining through a sieve, &c.) have, in common, the general attribute of separating matters confounded in a heap. Of separation there are two sorts: you may separate like from like (this has no established name)--or better from worse, which is called _purification_. Purification is of two sorts: either of body or of mind. In regard to body, the purifying agents are very multifarious, comprising not only men and animals, but also inanimate things: and thus including many varieties which in common estimation are mean, trivial, repulsive, or ludicrous. But all these various sentiments (observes Plato) we must disregard. We must follow out a real analogy wherever it leads us, and recognise a logical affinity wherever we find one; whether the circumstances brought together be vile or venerable, or some of them vile and some venerable, in the eyes of mankind. Our sole purpose is to improve our intelligence. With that view, all particulars are of equal value in our eyes, provided only they exhibit that real likeness which legitimates them as members of the same class--purifiers of body: the correlate of that other class which we now proceed to study--purifiers of mind.[23]