This paper argues that evidential clitics in St'át'imcets (a.k.a. Lillooet; Northern Interior Salish) introduce quantification over possible worlds and must be analyzed as epistemic modals. We thus add to the growing body of evidence suggesting that the functions of encoding information source and encoding epistemic modality are not necessarily distinct. However, St'át'imcets evidentials differ from English modal auxiliaries not only in that the former explicitly encode the source of the speaker's evidence, but also in that they do not encode differences in quantificational force. We therefore argue that distinguishing quantificational strength is not an intrinsic property of modal elements.With respect to the syntax-semantics interface, we argue on the basis of data from St'át'imcets against attempts to establish a universally fixed position for evidentials in the functional hierarchy. We conclude that evidentiality is not a homogeneous category, either semantically or syntactically. On the semantic side, cross-linguistically and even * We are very grateful to St'át'imcets consultants Gertrude Ned, Laura Thevarge, Rose Agnes Whitley and the late Beverley Frank. We are also very grateful to Rose-Marie Déchaine, Martina