  The word in the title translated ‘Mathematicians’ more literally means ‘learned’ (think of the suffix ‘-math’ in ‘polymath’), so some people translate the title ‘Against the Professors’; Blank (1998: xvi) suggests ‘Against the Professors of the Liberal Studies’; Cooper (2012: 429) suggests ‘Against the Theoreticians’; Bett 2018 translates the title ‘Against Those in the Disciplines’. (Mathematics in a stricter sense is the target of M III and IV.) In fact, not all eleven books united under the title Against the Mathematicians belong together: we are dealing here with two works. As is clear from the way M I opens and M VI closes, M I–VI constitute a complete work—the work which strictly speaking bears the title Against the Mathematicians (Blank 1998: xvi). The remaining books, M VII–XI, also go together. Their contents shadow very closely the contents of PH II (M VII &amp; VIII) and III (M IX–XI), expanding on them as appropriate (PH is, after all, just an ‘outline’). Janacek 1963 argues that M VII–XI form part of a larger work which was a lengthy elaboration of all the parts of PH; if this is right, then we have lost the book or books of that work which correspond to book I of the Outlines. (The observation that the larger work was an elaboration of PH is non-committal as to the order of composition of the two works. Janacek thought M was written after PH; against this, see Bett 1997: appendix C, and Schofield 2007: 321 n. 57.) The loss of the part corresponding to PH I is greatly to be regretted, since much of the philosophical interest surrounding Pyrrhonian skepticism comes out of Sextus’ description of it in PH I (indeed, most of this entry concerns PH I). Even though M VII–XI do not belong to the same work as M I–VI, it is customary amongst scholars to refer to all eleven books as M I–XI (Bett 2012: x).