A timeless question that has long challenged human thought is the opposition between Being (Parmenides) and Becoming (Heraclitus). One can see in Being, the underlying mathematical order of the physical world, and in Becoming, the chaos of this same world.Order Beneath Chaos explores the opposition between what can be called the impassive Logos — adopting a Greek terminology — and the disordered events that shake the universe and, in particular, our planet and our lives. After describing the Cosmic Web, where the struggle between Being and Becoming unfolds in its universal grandeur, the text explores the historical development of the Logos among the pre-Socratics, Plato, and post-Platonic thinkers. The age-old question of mathematical realism is then posed.To approach this question more precisely, the discussion moves on to the Logos of mathematicians, particularly the undecidabilities revealed by the logician Kurt Gödel, and then to the Logos of physicists (relativity, quantum mechanics). The ontology of the mathematical Logos leads to an extension of the notion of undecidability beyond mathematics itself, touching on philosophical and even metaphysical questions, thus revisiting the issue of mathematical realism. Although the answer to this question is logically undecidable, the author takes a stance in favor of a Platonic vision of the mathematical world while acknowledging that an opposing position is also possible.The final chapter then addresses, against the backdrop of logical undecidability, properly metaphysical issues — including the existence or non-existence of gods, as well as morality and values.