WHO knows not how in former times the Parmenides was by many contemplated at an awful distance as a gloomy sanctuary concealing treasures of the most exalted wisdom, and those accessible only to a few? But after this fancy, however natural it might be, had been though not till lately, set aside, that falsely grounded opinion of exalted wisdom was changed into objections of such a nature, that supposing the correctness of them, the whole only becomes inconceivable in another point of view. Or is it not to be thought inconceivable that a man of Plato’s genius and philosophical acuteness should either not have remarked the multiplicity of meanings in the words which involved him in the contradictions which he has accordingly written out for the world, with so much patience and without tracing their solution, or that he should have run his jokes with his still unpractised readers more mischievously than all the Sophists whom he so multifariously attacks, and that he should even have pushed the thing so far as to be in danger of fatiguing the instructed with the performance, or of disgusting them with the intention. To review, preliminarily, these objections and the different explanations of them, and to endeavour to set them aside individually or collectively, might contribute more than anything to render difficult the introduction of the reader into this dialogue, on other accounts sufficiently terrifying to many in many points of view. Hence it may be more advisable to state briefly the view which seems to be the correct one, as it may possibly approve itself sufficiently to give a standard whereby to judge of other opinions.
It is in general supposed that the Parmenides belongs to the later writings of Plato; but as this hypothesis rests upon hardly any other ground except a reluctance to give him the credit of having composed so profound a work in his youth, the reader may as easily admit the opposite assumption, preliminarily and only as hypothesis, and consider the Parmenides as belonging to the Phædrus and Protagoras. For as the Phædrus had only in general inspired and admiringly praised the philosophical impulse and its organ dialectics, while the Protagoras, artfully connecting the external and the internal, had exhibited by examples this philosophical passion and the sophistical pruriency, as well as the methods resulting from each of the two: so the Parmenides also shews itself to be a similar efflux from the Phædrus, inasmuch as it completes in another point of view what the Protagoras had begun, as a supplement to it and counterpart of it. For, in the Protagoras, the philosophical passion is considered as communicative, while in this dialogue it is represented in reference to the independent process of investigation which must precede communication: how, I mean, it looks in its purity to truth alone, and rejecting every collateral point, and all alarm at any result whatever, starts only upon the necessary assumption, that scientific knowledge is possible, and searches for it in well arranged excursions. There is, therefore, no want of opposition taken between the true and the false, but it is shown partly in Zeno, who works onwards to a definite point, the refutation of others, not without a consciousness of the inadmissibility of his weapons—to whose books, at that time generally known, the reader is almost tacitly referred; partly also in Socrates who does not yet go far enough, and from youthful apprehension, still confines himself within too narrow limits. That Plato did not by this intend to imply a censure upon his friend and master, we see, partly from the circumstance that in the earlier dialogues he attributes to him a genuine zeal for dialectics; partly, because in those pieces as well as in this he represents him as only in an earlier and imperfect stage of his philosophical career. Two things, however, may probably be looked for in this indication—on the one side, I mean, a censure upon those Socraticians who only applied themselves to ethics, and who upon that very account considered themselves more genuine scholars of the philosopher; on the other side hints for those who, overlooking, perhaps, in the Protagoras and the dialogues belonging to it the dialectic purpose and the speculative indications, would confound Plato with the class just mentioned. As then in this opposition, one side is only just indicated, so also is the other verbally set forth only in some particular expressions in the Parmenides, but shown in the main by the quiet manner in which the investigation, from which so many terrific results come out, is brought to a conclusion, and by the strictness of the method pursued in it. Now as regards the examples of philosophical investigations here chosen, the doctrine of correct division of ideas was attempted in the same way in the Protagoras; and it is there satisfactorily shewn why the philosophy of morals is chosen with that view, and every thing reduced to the question of the communicability of virtue. From the same grounds, then, and in the same spirit, in this dialogue in which investigation in the abstract is to be exhibited, the exercise is undertaken upon the doctrine of the mutual connection of ideas, as it is only by such connection, and not by separation, that knowledge can be really extended. And it is perfectly consistent with this, that in this dialogue the philosophy of nature predominates, and the highest question in it, that, namely, of the possibility of the knowledge of things, constitutes the centre-point, around which the whole moves in distant circles. Now it can hardly escape any one’s notice that such coincidence in tendency and inward form points to the same unaltered state of mind and to a similar view in the author. And all that I would regularly maintain is this, that the Parmenides has its origin in the same aims and youthful method with the Protagoras; not that Plato constructed it as a counterpart to the Phædrus and Protagoras, with a distinct consciousness of doing so, which is least of all to be ascribed to the youthful writer at that time, for now the youngest writers are often the oldest and most reflecting. We see also in the Parmenides decidedly more historical knowledge of science than in these two, and a more multifarious practice in philosophical art; but still there is a youthfulness in the manner in which these are brought into view, and put into the mouth of the great Parmenides himself.