This chapter examines Wilfrid Sellars’s idea of material inference – the view that there are valid inferences expressed in non-logical language that are irreducible to logical principles. Material inference can be characterised by three features: it is non-enthymemic, non-logical, and non-monotonic. However, the exact sense in which material inferences are valid remains unclear.After exploring various attempts to define the validity of material inference – such as through truth-preservation, analytic entailment, or reduction to general principles – I argue that material inference is not valid in the strict sense. Typically, validity refers to deductive validity, where the truth of the premises guarantees the truth of the conclusion.Nonetheless, pragmatists do not apply an external standard to our reasoning practices. Material inference can be understood not as valid, but as a legitimate and rationally authoritative form of reasoning. The key concept here is pragmatic propriety, which designates the social-normative entitlement to infer – rendering an inference either legitimate or illegitimate.