Leo Strauss in “The Mutual Influence of Theology and Philosophy”:

When we attempt to return to the roots of Western civilization, we observe soon that Western civilization has two roots which are in conflict with each other, the biblical and the Greek philosophic, and this is to begin with a very disconcerting observation. Yet this realization has also something reassuring and comforting. The very life of Western civilization is the life between two codes, a fundamental tension. There is therefore no reason inherent in the Western civilization itself, in its fundamental constitution, why it should give up life. But this comforting thought is justified only if we live that life, if we live that conflict, that is. No one can be both a philosopher and a theologian or, for that matter, a third which is beyond the conflict between philosophy and theology, or a synthesis of both. But every one of us can be and ought to be either the one or the other, the philosopher open to the challenge of theology or the theologian open to the challenge of philosophy.