 Relevant ideas can be traced in various aspects of Sextus’ philosophy. First, Sextus sides with anti-rationalist tendencies in medicine. According to these schools, a doctor remembers that, in earlier cases, symptom A was alleviated by medication B. They do not infer that medication B makes symptom A disappear, or that the illness C is the cause of symptom A. Second, the Five Modes do not exclusively target proof. They address everything that lends credibility to something else. They may thus also call into question signs that are taken as indicative of their causes. Sextus’ skeptic does not accept such indicative signs. Third, Sextus discusses the role of so-called commemorative signs in the skeptic’s life (PH 2.100–102; Allen 2001). For example, a scar is a commemorative sign of a wound. Both were co-observed in the past. A skeptic will think of a wound when seeing a scar. But they do not commit to causal or explanatory claims. Fourth, Sextus records a set of Causal Modes (PH 1.180–86), which are specifically targeted toward causal explanations (Corti 2014; on the relation between the Causal Modes and Hume cf. Garrett 2020). He does not ascribe the kind of relevance to them that the Ten Modes and the Five Modes have. Indeed, he thinks the Five Modes can do the work of Causal Modes (that is, call into question causal and explanatory theses and theories). However, the Causal Modes go into great detail on how the skeptic investigates any kind of causal thesis or theory.