Thinking and Singing
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Ultimately, what's the difference between serious thinking and poetical cogitation?
(Miles Davis comes to mind. His music is the embodiment of lucid lyricism.)
The best essay in this collection is by Robert Bringhurst, "The Philosophy of Poetry and the Trashing of Doctor Empedokles."
He cites this quotation from Giordano Bruno: "True philosophy is also music, poetry and painting; true painting, too, is music and philosophy; true poetry or music is a form of holy wisdom; so is painting."
So it would seem.
There is also an essay included entitled: "Philosophical Apokatastasis: On Writing and Return." Learn a new word and suddenly it's everywhere you look!
In this case, however, the essayist seems to be using the term as a fancy substitute for Plato's theory of epistemology--knowledge as recovered memories.