Mark Tobey fills his canvases with elliptical, calligraphic lines, beautiful whirls that seem at first glance to be completely abstract and to come from nowhere at all except his own subjective musing. But I shall never forget how struck I was, on visiting Tobey's studio one day, to see strewn around books on astronomy and photographs of the Milky Way. I knew then that Tobey experiences the movement of the stars and solar constellations as the external pole of his encounter.

Ch. 4 : Creativity and the Encounter, p. 80 - The Courage to Create (1975)