The Passions that most of all cause the difference of wit, are principally, the more or less constant adherence to their purpose; of which there is a degree more than that which in the former chapter I called tenacity. For in a man that is not volatile, and an inconstant wanderer of his imagination, but one that can fix his thoughts upon one certain point, and attend unto it without distraction, such are said to have a good Wit.
Leviathan, social contract