Blake has given us a treasure of insight, experience, and imagery. The cost to him of producing it was enormous. The reward was the satisfaction of using his innate gifts in expressing his imagination. That he produced a body of work that nourishes us two hundred years after his death, expresses the joy and gratitude with which he exercised his gifts. I like to think that in his case, "Eternity is in love with the productions of time." Marriage of Heaven and Hell, Plate 7, (E36)
From George W. Digby, Symbol and Image in William Blake, Page 19:
"He had as it were two eyes, an eye for the verbal image as it is spoken and written, and an eye for the pictorial image. The inner truth that he apprehended was something other than either of these, not confined or explicit in either of them, but something which could be expressed or implied by their means. For truth, reality, is always beyond the formulation of both words and of pictorial images. Sometimes the pictorial symbol parallels or amplifies the written one; sometimes gives the contrasting aspect, or opposite and contrary point of view. But always this double mode of expression is focused on man's subtle and complex nature, his illusions, self-deceptions, conceits, and his contradictory and insatiable desires. This twofold artistic capacity, and his vision of the infinite which the coarseness and opaqueness of human nature unnecessarily obscures, makes the creative work of Blake in art and poetry such an incomparable source of wisdom."
As Blake wrote in The Four Zoas on Page 35 (E324):
"What is the price of Experience do men buy it for a song
Or wisdom for a dance in the street? No it is bought with the price
Of all that a man hath his house his wife his children
Wisdom is sold in the desolate market where none come to buy
And in the witherd field where the farmer plows for bread in vain"