According to the plan already sketched: having now acquired some clear fundamental conceptions of the correlations among form, science, art, and the like notions often so vaguely used, we are next to inquire, as our first main line of research: Is it really true that what was explained as the growth in human personality is the continuing single principle of human progress; is it really true that the difference between the time of Æschylus and the time of (say) George Eliot is the difference in the strength with which the average man feels the scope and sovereignty of his age? For upon this fundamental point necessarily depends our final proposition that the modern novel is itself the expression of this intensified personality and an expression which could only be made by greatly extending the form of the Greek drama. Pursuing our custom of leaving the abstract and plunging into the concrete as soon as possible, let us determine this question by endeavoring to find some special notable works of antique and of modern times in which substantially the same subject matter has been treated; let us then compare the difference in treatment, let us summarize the picture of things evidently existing in the old, as contrasted with the modern author's and reader's minds; and finally let us see whether the differences thus emerging will not force themselves upon us as differences growing out of personality. For the purposes of this comparison I have thought that the _Prometheus Bound_ of Æschylus, the _Prometheus Unbound_ of Shelley, and the _Prince Deukalion_ of Bayard Taylor offered inviting resources as works which treat substantially the same story, although the first was written some two thousand three hundred years before the last two. Permit me then, in beginning this comparison, to set before you these three works in the broadest possible sketch by reading from each, here and there a line such as may bring the action freshly before you and at the same time elucidate specially the differences in treatment we are in search of. As I now run rapidly through the _Prometheus_ of Æschylus, I ask you to bear along in mind the precise nature of this spontaneous variation between man and man which I was at some pains to define in my first lecture; and perhaps I may extend profitably the partial idea there given by adopting a pretty fancy which I find in No. 44 of Tennyson's _In Memoriam_, and carrying it to a larger sphere than there intended. The poet is here expressing the conception that perhaps the main use of this present life of ours is for each one to learn _himself_,--possibly as preparatory to learning other things hereafter. He says: