Latin literature would be the poorer if the Satires of Persius had not survived. Many of course do not like his work because of a certain perceived incoherence or lack of shape or unity in his Satires, and many are of the opinion that their author was a student of books rather than of life: ‘an ideal example of an arrogant and spiritless young man wrapped up in poetry.’ As a merely academic poet, it is believed, Persius could do no more than depend heavily on poets who had gone before, and especially on Horace, reminiscences of whose work thickly lace the lines of Persius' satires. Furthermore, it is widely believed, Persius' ideas and the language in which they are expressed are often so obscure that it is impossible to interpret their meaning. The poet openly espoused a system he called iunctura acris, ‘the harsh collocation’ or ‘the surprising or illogical collocation’, by which he referred to a certain harsh, even violent, yoking together of ideas or images or words. The recent and most useful commentary by R. A. Harvey consistently interprets phrases by identifying them directly as iunctura acris, and a count of the occasions this definition is utilised (or resorted to) would be instructive. Persius' iunctura acris is evidently based on Horace's well-known callida iunctura, ‘the clever collocation’ (AP 47f.); but the changes wrought by Persius on this ‘shared’ phrase unequivocally mark the special characteristics of Persius' poetry, which are a sharp ferocity of expression and a certain aggressively extravagant imagination.