No More Learning

In Y eats the temptation o f Adams' reductive conversion o f mental into physical, a version o f which he pursued in "Sailing to Byzantium," is itself converted into a kind o f           equivocation:
Miracle, bird or golden handiwork, More miracle than bird or handiwork Planted on the star-lit golden bough, Can like the cocks of Hades crow,
Or, by the moon embittered, scorn aloud In glory o f changeless metal
Common bird or petal
And all complexities of mire or blood.