October 26. 1831
Keenness and Subtlety
Few men of genius are keen; but almost every man of genius is subtle. If you ask me the difference between keenness and subtlety, I answer that it is the difference between a point and an edge. To split a hair is no proof of subtlety; for subtlety acts in distinguishing differences—in showing that two things apparently one are in fact two; whereas, to split a hair is to cause division, and not to ascertain difference.