The third topic deals with those who are making progress in philosophy. It's about keeping the other two topics secure, so that no impression catches us off guard — not in sleep, not when drunk, not when depressed. You might say this is beyond our power. But today's philosophers ignore the first two topics (emotions and duties) and focus only on the third. They use tricky arguments, draw conclusions from questions, and work with hypotheses — basically, they lie. They say a person working on these matters must be careful not to get deceived. Who must? The wise and good person. So this is all you're missing, right? Have you mastered everything else? Are you immune to deception when it comes to money? When you see a beautiful woman, do you resist the temptation? When your neighbor inherits property, are you not bothered? Is the only thing you lack an unshakeable mind?
The third topic is that which immediately concerns those who are making proficiency, that which concerns the security of the other two, so that not even in sleep any appearance unexamined may surprise us, nor in intoxication, nor in melancholy. This, it may be said, is above our power. But the present philosophers neglecting the first topic and the second (the affects and duties), employ themselves on the third, using sophistical arguments ([Greek: metapiptontas]), making conclusions from questioning, employing hypotheses, lying. For a man must, it is said, when employed on these matters, take care that he is not deceived. Who must? The wise and good man. This then is all that is wanting to you. Have you successfully worked out the rest? Are you free from deception in the matter of money? If you see a beautiful girl do you resist the appearance? If your neighbor obtains an estate by will, are you not vexed? Now is there nothing else wanting to you except unchangeable firmness of mind ([Greek: ametaptosia])?