  By far the longest single discussion in PH I concerns the modes of Skepticism (I 31–186) (see Annas and Barnes 1985; Barnes 1990a,b; Striker 1993; Hankinson 1995: chapters 9 and 10; Perin 2006: 354–8; Woodruff 2010; Morison 2011, 2018; Bullock 2016). These are announced as being means by which the Skeptic comes to suspension of judgment (I 35). Recall that the Skeptic achieves his characteristic state of suspension of judgment (epochê), with respect to some proposition or other, by assembling arguments or considerations on both sides (PH I 12). The Skeptic needs techniques or tools to bring this suspension about. The modes divide into four groups, the Ten Modes, the Five Modes, the Two Modes, and the Eight Modes. (Presumably the Skeptic can employ methods other than the modes for bringing about suspension of judgment. For extended analysis of one such method, that of ‘reversal’, see Castagnoli 2010: ch. 14.)