Read it through once

It is not meant by this that I shall undertake to treat of the Poetic Art as a whole — of all the littératures of the world, and of Poetry in all its forms. First, because the limits assigned to the present paper would not permit so extended a discussion; and secondly, because such a discussion would be beyond my knowledge. I shall, therefore, confine myself to certain elementary, general truths which seem to me essential to the poetical, and particularly to the purely poetical, effect.