It is ideas, as distinct from purposes, that make immortality — ideas as form and not as substance. In art everything is form, and everything includes ideas. It does not matter to the judgement of posterity whether a poem contains materialist or idealist notions; it matters whether these notions are high or not, agreeable in their form — even their mental and abstract form — or disagreeable.

This would seem to make propaganda not injurious to art, so long as there is art. It is indeed not essentially injurious, but, that it may not so be, it is necessary that, against his own purpose and intent, the artist forget the propaganda in the art. It may be that the “Divine Comedy” is intended to be Catholic propaganda — a rather futile thing in Catholic times; but Dante, when he wrote it, forgot all about the propaganda and wrote poetry. The propaganda does no harm to the poetry, for the simple reason that it did not get there. The result is that a third of Dante’s commentators consider the “Divine Comedy” heretical, and many of these as purposely so. If the poem can be considered as Catholic and anti-Catholic, the propaganda is certainly not very efficacious. The same applies to the kindred and different poem which stands beside the “Divine Comedy” on the sorting of the ages. Milton wrote it down as his purpose to justify the ways of God to man, and his poem contains two heroes — Satan, who revolts against God, and Adam whom God has punished. He has justified the ways of man to God. His poem is set up an epic for one form of Christianity, and the result is that the author was an Arian, his form of Christianity being the absence of Christianity. (His vast learning and experience of the learnt has put everything into his Christian epic; the only thing left out was Christ. Has anyone ever felt Christian after reading “Paradise Lost”?).

It may be said that, so long as propaganda is not serious, it is compatible with art. The sacred enthusiasm which lasts only one moment is the right soul with which to defend a noble or ignoble cause and leave it art. The most unpatriotic poem of a great poet is, says Swinburne in defending art for art’s sake, better than the most patriotic one of a bad one. That is true, and it is probably so because the unpatriotic poem was not sincere, and the poet had time to think more about the poetry than about the antipatriotism.