Perhaps Lessing’s greatest glory is that he has given answer to the despairing question which his master quoted in the Ethics.[68] “If the water chokes, what must one drink on the top of it?” “More and purer water” is that answer, of course: and Lessing scoured the clogged and stagnant channels of Neo-Classicism by recurrence to the original fount. Of course he was not himself absolutely original. He owed something to Heinsius, in that most remarkable tractate to which we did justice in its place, among the more distant moderns, to Dacier, pedant as he is, to Brumoy, to Hurd among the nearer. But more than to any of them he devoted himself to the real text of the _Poetics_, interpreted by a combination of scholarship and mother-wit. To this day he has to be consulted upon the _cruces_ of Fable and Character, of Unity, of knotting and unknotting, of _katharsis_.[69] That he has said no final word on them matters nothing: final words are not to be said on things of opinion and probability Until God’s great _Venite_ change the song. But on these and not a few other matters he reorganised the whole method and the whole tenor of the inquiry. And so he not only earns his own place in the story, but half unintentionally establishes, or helps us to establish, the great truth that the whole _is_ a story, a history, a chain of opinion and comment on opinion, now going more, now less, right, but to be kept as a chain. [Sidenote: _With whom he combines Diderot._] Nothing can illustrate this better than the fact that Lessing’s second master in criticism is—Diderot! He does not regard that erratic and _cometic_ genius as he regards Aristotle, he does not think the _Bijoux Indiscrets_, and the remarks on the _Fils Naturel_, and the rest, as being “as infallible as the _Elements of Euclid_.”[70] He would have disqualified himself from serious consideration if he had. He dissents from some of Diderot’s opinions; he combats some of his arguments. But he admits, almost in so many words, and in a constant attitude which is more valuable than any verbal admission, that this most irregular, revolutionary, _casual_ of modern thinkers has set him on his own path of independent revaluation of critical principles. [Sidenote: _His deficiencies in regard to mediæval literature._]