  The Quinean approach identifies the logical constants as the expressions that play a privileged, “structural” role in a systematic grammatical theory for a language. An alternative approach, due to Quine’s student  Donald Davidson,  identifies the logical constants as the expressions that play a privileged, “structural” role in a systematic theory of meaning for a language. A Davidsonian theory of meaning takes the form of a  Tarskian truth theory.  Thus, it contains two kinds of axioms: base clauses that specify the satisfaction conditions of atomic  sentences,[6]  and recursive clauses that specify the satisfaction conditions of complex sentences in terms of the satisfaction conditions of their proper  parts.[7]  For example: