Francesco Guicciardini quotes
Frank sincerity is a quality much extolled among men and pleasing to every one, while simulation, on the contrary, is detested and condemned. Yet for a man's self, simulation is of the two by far the more useful; sincerity tending rather to the interest of others. But since it cannot be denied that it is not a fine thing to deceive, I would commend him whose conduct is as a rule open and straightforward, and who uses simulation only in matters of the gravest importance and such as very seldom occur; for in this way he will gain a name for honesty and sincerity, and with it the advantages attaching to these qualities. At the same time, when, in any extreme emergency, he resorts to simulation, he will draw all the greater advantage from it, because from his reputation for plain dealing his artifice will blind men more.
Francesco Guicciardini