–when John Marin’s father suggested that the younger Marin “do salable etchings in the mornings, and his crazy watercolors in the afternoons”–” that [he] ask his new wife whether a woman could be a prostitute in the morning and a virgin in the afternoon”, which Stieglitz felt was equivalent to what Marin was asking his son to do.
That is from the sidebar of the dead tree version of this article on John Marin.
The sidebar contains a lot of good stuff, and I wish they’d put that up on the site, also.