(1) At this point they both looked at me and signalled that they were ready to hear me. I began by saying, ‘Let me first of all beg you not to expect me to expound a formal lecture to you like a philosopher. Indeed this is a procedure I have never greatly approved of even in the case of philosophers. After all, when did Socrates, who may justly be called the father of philosophy, ever do such a thing? It was, rather, the method of those known at the time as sophists. Gorgias of Leontini was the first of their number bold enough, at a public meeting, to “invite questions”, that is, to ask anyone to name a topic for him to speak on. A daring venture – I would have called it impudent, had this procedure not been adopted later by our own philosophers.

(2) ‘But we know from Plato that Gorgias and the other sophists were mocked by Socrates. Socrates’ own technique was to investigate his interlocutors by questioning them. Once he had elicited their opinions in this way, he would then respond to them if he had any view of his own. This method was abandoned by his successors, but Arcesilaus revived it and laid it down that anyone who wanted to hear him speak should not ask him questions but rather state their own opinion. Only then would he reply.

In June 45 Marcus Tullius Cicero composed On Moral Ends, a treatment in three dialogues, over five books, of fundamental issues of moral philosophy. The sixty-one year old Cicero, a Roman statesman with an eventful and distinguished career, had gone into political retirement during the ascendancy to supreme power of Julius Caesar after a turbulent period of civil war, in which Cicero had ended up on the losing side. His personal life had also fallen apart. In 46 he divorced Terentia, his wife of thirty years, and married his young ward Publilia. The marriage broke up less than a year later, partly because of Cicero's extreme sorrow at the death in childbirth of his much–loved daughter Tullia, together with her baby, in February 45. A productive writer, he decided to use his enforced and grief-stricken leisure to introduce educated Romans to major parts of the subject of philosophy in their own language, rather than leaving them to read the originals in Greek. On Moral Ends is the most theoretical of the works on moral philosophy, accompanied by more specialized discussions in On Duties and Tusculan Disputations and the more ‘applied’ Friendship, Old Age and Reputation.

On Moral Ends is a substantial work of moral philosophy. There have been periods when it has been an influential part of the discourse of moral theory, and it has always been a valuable source for the three moral theories it discusses, those of Epicurus, the Stoics and Antiochus (the last a hybrid influenced by Aristotle).

(1) With that, Cato concluded his discourse. ‘For a theme so large and obscure’, I said, ‘your exposition was as accurate as it was lucid. Either I should altogether give up on the idea of responding, or else at least take some time out for reflection. In both its foundations and in the edifice itself Stoicism is a system constructed with great care; incorrectly, perhaps, though I do not yet dare pronounce on that point, but certainly elaborately. It is no easy task to come to grips with it.’

‘Is that so?’ Cato replied. ‘In court I see you, under this new law, delivering the case for the defence on the same day and finishing up within three hours. Do you think I am going to grant you a deferral in this case? Mind you, you will find your brief no sounder than some of those you occasionally manage to win. So handle this one in the same way. Others have, after all, dealt with the topic, as you have yourself often enough, so you cannot be lacking in material.’

(2) To this I replied: ‘Steady on! I am not in the habit of mounting reckless attacks on the Stoics. I am by no means in complete agreement with them, but humility restrains me: there is so much in Stoicism that I barely understand.’ ‘I admit’, said Cato, ‘that there are some obscure elements.