Big fleas have little fleas upon their back to bite ’em

This humurous proverbial saying sounds of fairly recent coinage and of the kind that is associated with 20th century writers like Ogden Nash and Dorothy Parker. However, it is much older than that.

It is usually listed as being coined by the English mathematician Augustus De Morgan in the 19th century.

That’s true up to a point. To find the actual source we need to go back a century again. De Morgan gave us the line in the form we now use it, but he copied it from an earlier form of the same thought, which was coined by the Anglo-Irish satirist Jonathan Swift.

The two forms of the proverb are – Swift’s original, from his satirical poem On Poetry: A Rapsody, 1733:

The Vermin only teaze and pinch
Their Foes superior by an Inch.
So, Nat’ralists observe, a Flea
Hath smaller Fleas that on him prey,
And these have smaller yet to bite ’em,
And so proceed ad infinitum:
Thus ev’ry Poet, in his Kind
Is bit by him that comes behind

De Morgan’s variant, from his book A Budget of Paradoxes, 1872, is:

Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.