  Moss' theorem, which relates Massey products in the $E_r$-page of the
classical Adams spectral sequence to Toda brackets of homotopy groups, is one
of the main tools for calculating Adams differentials. Working in an arbitrary
symmetric monoidal stable topological model category, we prove a general
version of Moss' theorem which applies to spectral sequences that arise from
filtrations compatible with the monoidal structure. The theorem has broad
applications, e.g. to the computation of the motivic slice and motivic Adams
spectral sequences.
