phantasmagoria, ghostly symbols of a truth which cannot be otherwise
conveyed, at least by Mr Yeats. To this, in itself, we make no demur.
The poet, if he is a true poet, is driven to approach the highest
reality he can apprehend. He cannot transcribe it simply because he does
not possess the necessary apparatus of knowledge, and because if he did
possess it his passion would flag. It is not often that Spinoza can
disengage himself to write as he does at the beginning of the third book
of the Ethics, nor could Lucretius often kindle so great a fire in his
soul as that which made his material incandescent in _Æneadum genetrix_.
Therefore the poet turns to myth as a foundation upon which he can
explicate his imagination. He may take his myth from legend or familiar
history, or he may create one for himself anew, but the function it
fulfils is always the same. It supplies the elements with which he can
build the structure of his parable, upon which he can make it elaborate
enough to convey the multitudinous reactions of his soul to the world.

But between myths and phantasmagoria there is a great gulf. The
structural possibilities of the myth depend upon its intelligibility.
The child knows upon what drama, played in what world, the curtain will
rise when he hears the trumpet-note: 'Of man's first disobedience....'
And, even when the poet turns from legend and history to create his own
myth, he must make one whose validity is visible, if he is not to be
condemned to the sterility of a coterie. The lawless and fantastic
shapes of his own imagination need, even for their own perfect
embodiment, the discipline of the common perception. The phantoms of the
individual brain, left to their own waywardness, lose all solidity and
become like primary forms of life, instead of the penultimate forms they
should be. For the poet himself must move securely among his visions;
they must be not less certain and steadfast than men are. To anchor
them he needs intelligible myth. Nothing less than a supremely great