In an earlier study I argued that the appearance of the name of Memmius in the first, second, and fifth books alone of Lucretius de Rerum Natura is only the most striking indication of a fundamental change in the poet's attitude towards his reader which is already well established quite a short way through book 5, and which makes it almost incontestable that Lucretius wrote books 3, 4, and 6 after he had lost all hope of converting Memmius to Epicureanism.