A son asks his father about the nature of thought and belief: why do we so easily think the invisible, the extraordinary, that which we cannot prove? Rather than resort to ready-made answers, the father chooses to propose a bold hypothesis: our brain has a uterine origin, and it retains traces of the environment in which it was formed-rhythms, pressure, exchanges, filtered sounds, diffuse light. In the womb, on this view, the brain learns the world's first grammar: that of the Self (inner sensations), that of the Other (affective bonds), and that of the Extracorporeal (what lies beyond the body's membrane). This silent schooling shapes our capacity to perceive meaning in chaos, our patterns of trust, our expectancy for mystery. Thus belief does not arise as a mistake or an illusion, but as a fundamental structure of the mind: we were trained, even before birth, to believe in the invisible that sustained us. For this reason we continue, after birth, to seek sheltering penumbras, regular cycles, signs of belonging- inner and extraordinary. From this pursuit spring both religion and science, the arts, narratives, myths, and even collective obsessions. The hypothesis is that we all share, to some extent, the same "uterine alphabet" that crosses cultures, eras, and traditions. This biological heritage makes possible both creation and superstition, astronomical calculation and the myth of the comet. The father shares with the son an intimate reflection that joins science, philosophy, and imagination: to think is to carry uterine learning forward into the real world. I believe we will not be able to shake off the extracorporeal that uterine structured us-and that may be our good fortune. In the end, a conversation becomes an invitation to infinite curiosity-a dialogue between generations, two inhabitants of the same ancestral womb, walking together along the question that never runs out: why do we think, and why can we not stop believing?
