On 15 July, it would appear, Petrarch finished work on a manuscript of Terence: a manuscript of that author now in Parma has a subscription, written in 1470 by one Gianluigi Sacca, in which he states that he has copied it
ad quoddam exemplar scriptum et undique reuisum per disertissimum et excellentissimum poetam Dominum Franciscum Petrarcam de anno mccclviij UIlii XV in sero.1
At some time in July, evidently, Petrarch learned that Laelius' unhappiness had been due to his belief that Socrates had turned against him, and in particular that Socrates had spoken ill of him in a letter to Petrarch. Greatly distressed, Petrarch on 30 July wrote to Laelius a letter, Fam. XX13, in which, with a fine combination of reasoning, reproachfulness, affection, and adjuration, he denies that Socrates had ever spoken ill of him in any of his letters, and maintains that Socrates could not possibly have spoken so to anyone, least of all to him (Petrarch). After a reference to members of the Colonna family who had been benefactors to Laelius, to Socrates, and to Petrarch alike, the letter culminates in this passage:
For the sake of those, men, I say, for my sake, and for your own sake I beg you to relieve me speedily of distress, which weighs me down and burns me and twists me and tortures me; and if you love me, or have ever loved me, then I beg you, before this letter leaves your hands, to seek out Socrates--who is astounded by the change that has come over you and is sorely vexed by his own ill fortune--or else to bid him to come to you.