This paper intends to question the conventional wisdom that philosophy should limit its endeavours to the horizon of modern transcendentalism, thus rejecting the presuppositions of faith. By reappraising Edith Stein's views of faith and reason, which are also shared by the magisterial document of John Paul II, Fides et ratio, an argument for the possibility of “thinking in faith” is put forward. But why would it be important nowadays to engage in rational research in philosophy in a quest for truth which also draws its inspiration from faith? First of all, as I shall argue, because the two great modern transcendental projects, namely the Kantian and the Husserlian one, which were both in tune with Spinoza's project to liberate philosophical reason from theology, have failed. Secondly, because “faith” (fides) is not based on “irrational sentiments,” but is “intellectual understanding,” as Edith Stein argues. Third, because the natural light of the created intellect is, as was shown by St. Thomas Aquinas, a participated likeness of the supernatural light of the uncreated divine intellect. Therefore, even the natural philosopher gets their own light from the eternal Truth of faith. Finally, by following another Thomistic stance, one may argue that the end of human life is an intelligible one: the contemplation of God. In order to attain this end, the human being should endeavour to attain as much as is possible, in an intelligible way, the thing desired. Even if the philosophical inquiry has its own limits, it may however sustain such progress towards the end of human life.