Have waves enough to quench it; nor on earth
Is fuel enough to feed,
While day sows night, and night sows day for seed.

This intensity of perception is largely the result, or the cause, of the
poet's unusually sensitive consciousness of the ephemeralness of love.
The notion of permanence often seems to rob love of all its poetical
quality. The dark despair engendered by a sense of its transience is
needed as a foil to the fiery splendors of passion. Thus Rupert Brooke,
in the sonnet, _Mutability_, dismisses the Platonic idea of eternal
love and beauty, declaring,

Dear, we know only that we sigh, kiss, smile;
Each kiss lasts but the kissing; and grief goes over;
Love has no habitation but the heart:
Poor straws! on the dark flood we catch awhile,
Cling, and are borne into the night apart,
The laugh dies with the lips, "Love" with the lover.

Sappho is represented as especially aware of this aspect of her love.
Her frenzies in _Anactoria_, where, if our hypothesis is correct,
Swinburne must have been terribly concerned over his natural coldness,
arise from rebellion at the brevity of love. Sappho cries,

What had all we done
That we should live and loathe the sterile sun,
And with the moon wax paler as she wanes,
And pulse by pulse feel time grow through our veins?

Poetry, we are to believe, arises from the yearning to render eternal