V. I. Arnold asserted that mathematics is a natural science: "Mathematics is a part of physics. Physics is an experimental science, a part of natural science. Mathematics is the part of physics where experiments are cheap." V.I. Arnold: "On teaching mathematics" (1997)
This opinion is rare. Many mathematicians will oppose, in particular pure mathematicians. But is it solitary?
Are there famous mathematicians who have shared in written form Arnold's view that mathematics is a natural science?