We might think of a philosophy as having a shape, a form, or an image given by its presumed ultimate authority regarding the good, the true, and the beautiful. A rationalist philosophy that has just pure reason as its ultimate authority might be said to have a purely rational form, and an empiricist philosophy that has just empirical experience as its ultimate authority might be said to have a purely empirical form. In addition, a philosophy that has just sound arguments as its ultimate authority can be said to have a purely argumentational form.

A distinctly Christian philosophy would be neither purely rational nor purely empirical nor purely argumentational in form. Instead, it would accommodate the subversive Christian message that the outcast Galilean “Jesus is Lord” (1 Cor. 12:3; see Acts 2:36). In its talk of “Lord” (kurios), this message assigns distinctive authority to Jesus Christ, even the authority proper to God (see, for instance, Phil. 2:9–11). The claim that Jesus is Lord figures not only in who counts as a Christian (namely, the one for whom Jesus is Lord) but also in which philosophy counts as Christian (namely, the one for whom Jesus is Lord).