Plato has not followed out the hint which he has here put into the mouth of Sokrates in the Parmenidês--That the Ideas or Forms are conceptions existing only in the mind. Though the opinion thus stated is not strictly correct (and is so pointed out by himself), as falling back too exclusively on the subjective--yet if followed out, it might have served to modify the too objective and absolute character which in most dialogues (though not in the Sophistês) he ascribes to his Forms or Ideas: laying stress upon them as objects--and as objects not of sensible perception--but overlooking or disallowing the fact of their being relative to the concipient mind. The bent of Plato's philosophy was to dwell upon these Forms, and to bring them into harmonious conjunction with each other: he neither took pains, nor expected, to make them fit on to the world of sense. With Aristotle, on the contrary, this last-mentioned purpose is kept very generally in view. Amidst all the extreme abstractions which he handles, he reverts often to the comparison of them with sensible particulars: indeed Substantia Prima was by him, for the first time in the history of philosophy, brought down to designate the concrete particular object of sense: in Plato's Phædon, Republic, &c, the only Substances are the Forms or Ideas. [Side-note: Continuation of the Dialogue--Parmenides admonishes Sokrates that be has been premature in delivering a doctrine, without sufficient preliminary exercise.] Parmenides now continues the debate. He has already fastened upon Sokrates several difficult problems: he now proposes a new one, different and worse. Which way are we to turn then, if these Forms be beyond our knowledge? I do not see my way (says Sokrates) out of the perplexity. The fact is, Sokrates (replies Parmenides), you have been too forward in producing your doctrine of Ideas, without a sufficient preliminary exercise and enquiry. Your love of philosophical research is highly praiseworthy: but you must employ your youth in exercising and improving yourself, through that continued philosophical discourse which the vulgar call _useless prosing_: otherwise you will never attain truth.[41] You are however right in bestowing your attention, not on the objects of sense, but on those objects which we can best grasp in discussion, and which we presume to exist as Forms.[42] [Footnote 41: Plato, Parmenid. p. 135 C. [Greek: Prô\| ga/r, pri\n gumnasthê=nai, ô)= Sô/krates, o(ri/zesthai e)picheirei=s kalo/n te/ ti kai\ di/kaion kai\ a)gatho\n kai\ e(\n e(/kaston tô=n ei)dô=n . . . kalê\ me\n ou)=n kai\ thei/a, ei)= i)/sthi, ê( o(rmê\ ê(\n o(rma=|s e)pi\ tou\s lo/gous; e(/lkuson de\ sauto\n kai\ gumna/sai, ma=llon dia\ tê=s dokou/sês a)chrê/stou ei)=nai kai\ kaloume/nês u(po\ tô=n pollô=n a)doleschi/as, e(/ôs e)/ti ne/os ei)=; ei) de\ mê\, se\ diapheu/xetai ê( a)lê/theia.]] [Footnote 42: Plato, Parmenid. p. 135 E.]