It has often been separately published.  In 1600 it was included by Martin Haynoccius in an Enchiridion Ethicum, containing also Plutarch’s two tracts on the education of boys and the study of the poets, with which it is interesting to compare it.  Grotius published it with Plutarch’s De Legendis Poetis at Paris in 1623.  They were also published together by Archbishop Potter at Oxford in 1691.