From somewhere towards the back of volume 1, on his first arrival in Rome.
The man fit to make a fortune in this ancient capital of Italy must be a chameleon sensitive to all the colors which the light casts on his surroundings. He must be flexible, insinuating, a great dissimulator, impenetrable, obliging, often base, ostensibly sincere, always pretending to know less than he does, keeping to one tone of voice, patient, in complete control of his countenance, cold as ice when another in his place would be on fire; and if he is so unfortunate as not to have religion in his heart he must have it in his mind, and , if he is an honest man, accept the painful necessity of admitting to himself that he is a hypocrite. If he loathes the pretense, he should leave Rome and seek his fortune in England. Of all these necessary qualities – I do not know if I am boasting or admitting my deficiency – I possessed only obligingness, which, without the others, is a fault. I was an interesting fool, a rather fine horse of a good breed, but unbroken or, what is worse, badly broken.