"Philosophy denounces nihilism as an obscurantism " this is the very last sentence of the researches presented in Reflections: the Way of Reason and the Labyrinth of nihilism and it is the proposition that ends a long theoretical quest that has investigated anew the most well-known debates about the philosophy of Being and that has led to the discovery of a complex logical and theoretical structure, a very complex thought, that is common to all of the philosophers of Being, no matter how distant and different they are from each other in time and cultural temperament. The research begins with the analysis of the frontal clash of Plato's Sophist and Parmenides' philosophy and continues with a detailed study of Parmenides' texts. These analyses reveal that a fundamental logical and theoretical structure of Parmenides' thought has been long ignored, and this in turn required the detailed exploration of other decisive debates in which a strong philosophy of Being has been opposed by great philosophers. The primary example is the case of Kant opposing Descartes' arguments about metaphysics, which of course entails a detailed study of Descartes' positions about the philosophy of Being, and their roots in Saint Anselm's works. When directly confronted with the complex logical and theoretical structure of the philosophy of Being, the arguments of the opponents of the philosophy of Being appear shallow and self-contradictory, ultimately a series of repeated fallacies. The intrinsic necessity of the arguments of the philosophers of Being, and the complex logical and theoretical structure of their thought, have not been investigated before, and the researches of Reflections: the Way of Reason and the Labyrinth of nihilism reveal a great danger for philosophy: the risk of falling into absolute irrationalism. Contemporary nihilism, with its absolute self-contradictions, is just the worst example of such irrationalism. But at the same time these researches discover a solid foundation for the philosophy of Being, solid enough to denounce any form of nihilism as a fallacy and to assert that the philosophy of Being is the only way of reason. Thus, the researches presented in Reflections: the Way of Reason and the Labyrinth of nihilism prove that the doom of irrationalism and nihilism was not and is not either inevitable or necessary, and that, as Pascal taught, we can still ascend to the shoulders of the giants of thought and from there we can extend our sight to a very new, and very ancient, knowledge and we can hear the promise of deeper and subtler wisdom.