Try to put well in practice what you already know; and in so doing, you will in good time, discover the hidden things which you now inquire about. Practice what you know, and it will help to make clear what now you do not know.

Rembrandt van Rijn, as quoted in A Dictionary of Thoughts: Being a Cyclopedia of Laconic Quotations from the Best Authors of the World, both Ancient and Modern (1908) by Tryon Edwards, p. 131