In the present paper we revisit and analyze the thought of John Wippel on the topic of the legitimacy or otherwise of a Christian philosophy, a debate which involved some of the towering figures of twentieth-century European philosophy, such as Étienne Gilson, Jacques Maritain, and Fernand Van Steenberghen. Wippel’s Thomistic appraisal of the possibility of a Christian philosophy values the key distinction between the order/moment of discovery and the order/moment of proof. This distinction allows him to accept the expression in the first order/moment, but not in the second. His understanding of the issue captures two essential aspects, which any debate around Christian philosophy should always safeguard. The first aspect is methodological, since it distinguishes between philosophy and theology, reason and faith. The second aspect is existential, because it stresses the personal character of the philosophical quest undertaken by every Christian philosopher. For these reasons, Wippel’s classic, Thomistic understanding of the concept of Christian philosophy is still relevant today, and deserves to be rediscovered.