From Bacon's Wisdom of the Ancients: VIII Endymion:

"This fable seems to describe the tempers and dispositions of princes, who, being thoughtful and suspicious, do not easily admit to their privacies such men as are prying, curious, and vigilant, or as it were sleepless, but rather such as are of an easy obliging nature and indulge them in their pleasures, without seeking anything farther, but seeming ignorant, insensible or as it were, lulled asleep before them."

From Shakespeare's Julius Caesar:

"Let me have men about me that are fat, sleek-headed men, and such as sleep o'nights.
Yond Cassius has a lean and hungry look
He thinks too much. Such men are dangerous."