"For scholars and laymen alike it is not philosophy but active experience in mathematics itself that can alone answer the question: What is mathematics?"

This quote by Richard Courant recommends that the best way to understand mathematics is to actively engage with it. He implies that it is insufficient to simply check out mathematics or to think of it philosophically. Instead, it is through direct experience with mathematics that a person can really comprehend it. Courant suggests that this is true for both scholars and laymen, as everyone can take advantage of engaging with mathematics. He implies that it is just through active experience that one can respond to the concern of what mathematics is. This quote encourages people to check out mathematics and to acquire a much deeper understanding of it through direct experience.