Yeats points to three different constructions of the world:
Platonic forms: where nature is only a transient phenomenon.
Aristotle: the philosopher of the natural world, his experiments grounded in scientific objectivity.
Pythagoras: the philosopher of aesthetics, famous for establishing musical ratios and the ideal form of the golden triangle.
These philosophers
were preeminent in establishing the philosophy of thought, science and aesthetics.
However, Yeats states that while their philosophical ideas might linger, even
great luminaries grow old, become objects of ridicule and die. Describing them
as old scarecrows, Yeats reflects upon their and his own impermanence.
Another area for Yeats contemplation is the arts. Yeats was involved in
all the arts: music, dance, theater, poetry, painting and sculpture. He considered
them as one art, all attempting to find the perfect Pythagorean aesthetic ratios.
The third area of Yeats reflection was his view of himself as a lover. Beset
by love for one woman for many years, Yeats describes the intimate feeling when
his beloved grants him a vision of the life that she led prior to their meeting.