“In reality, there is, perhaps, no one of our natural passions so hard to subdue as pride.”
Franklin treats humility as a continuing discipline rather than a completed achievement: pride is difficult precisely because it can survive attempts to suppress it and can even attach itself to the appearance of modesty.
Source details
The Autobiography of Benjamin Franklin, Part II, Humility discussion near the close of the Passy 1784 continuation. Franklin reflects that pride survives attempts to suppress it and can attach itself even to apparent humility; the reviewed direct locator is Wikisource Section Thirty Nine.