M. Tullius Cicero, De Officiis
Walter Miller, Ed.

[90] 26. Again, when fortune smiles and the stream¹ of life flows according to our wishes, let us diligently [p. 93] avoid all arrogance, haughtiness, and pride. For it is as much a sign of weakness to give way to one's feelings in success as it is in adversity. But it is a fine thing to keep an unruffled temper, an unchanging mien, and the same cast of countenance in every condition of life; this, history tells us, was characteristic of Socrates and no less of Gaius Laelius. Philip, king of Macedon, I observe, however surpassed by his son in achievements and fame, was superior to him in affability and refinement. Philip, accordingly, was always great; Alexander, often infamously bad. There seems to be sound advice, therefore, in this word of warning: “The higher we are placed, the more humbly should we² walk.” Panaetius tells us that Africanus, his pupil and friend, used to say: “As, when horses have become mettlesome and unmanageable on account of their frequent participation in battles, their owners put them in the hands of trainers to make them more tractable; so men, who through prosperity have become restive and over self-confident, ought to be put into the training-ring, so to speak, of reason and learning, that they may be brought to comprehend the frailty of human affairs and the fickleness of fortune.”