Practice What You Know

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 Harmenszoon van Rijn (15 July 1606 - 4 October 1669), Dutch draughtsman, painter, and printmaker, generally considered one of the greatest visual artists in history, as cited 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