John Gardner said this quote

This highest kind of truth is never something the artist takes as given. It's not his point of departure but his goal. Though the artist has beliefs, like other people, he realizes that a salient characteristic of art is its radical openness to persuasion. Even those beliefs he's surest of, the artist puts under pressure to see if they will stand.

~ John Gardner

As every writer knows... there is something mysterious about the writer's ability, on any given day, to write. When the juices are flowing, or the writer is 'hot', an invisible wall seems to fall away, and the writer moves easily and surely from one kind of reality to another... Every writer has experienced at least moments of this strange, magical state. Reading student fiction one can spot at once where the power turns on and where it turns off, where the writer writes from 'inspiration' or deep, flowing vision, and where he had to struggle along on mere intellect.

~ John Gardner

The best way a writer can find to keep himself going is to live off his (or her) spouse. The trouble is that, psychologically at least, it’s hard. Our culture teaches none of its false lessons more carefully than that one should never be dependent. Hence the novice or still unsuccessful writer, who has enough trouble believing in himself, has the added burden of shame. It’s hard to be a good writer and a guilty person; a lack of self-respect creeps into one’s prose.

~ John Gardner

I know everything, you see,' the old voice wheedled. 'The beginning, the present, the end. Everything. You now, you see the past and the present, like other low creatures: no higher faculties than memory and perception. But dragons, my boy, have a whole different kind of mind.' He stretched his mouth in a kind of smile, no trace of pleasure in it. 'We are from the mountaintop: all time, all space. We see in one instant the passionate vision and the blowout.

~ John Gardner