We must have already discussed this in a thread somewhere (perhaps it is as yet unfiled). The article talks about the various manuscripts.
Nor was the tenth book left much longer without a commentator. In due time the energies of Gassendi were concentrated upon it. Both the physical speculations and the ethical doctrine of Epicurus attracted him, and there appeared at Leyden in 1649 Animadversiones in librum X Diogenis Laertii, with a companion volume, De vita et moribus Epicuri. A second edition followed, and a third (Leyden, 1675), in which the two parts, Epicuri philosophiae per Petrum Gassendum, tomus primus, and Epicuri ethicae per Petrum Gassendum, tomus secundus, were united. Gassendi depended less upon MSS. than upon common sense and his own reasoning powers ; nevertheless to him, as to his predecessors, Stephanus, Casaubon, and Aldobrandinus, are due some conjectural restorations of the text which subsequent editors accept without reserve ; for example, there are three such in x. 83.
Diogenes Laertius: the Manuscripts of "The Lives of Eminent Philosphers"
