Nearly 400 years ago, René Descartes pointed to a tiny structure in the center of the brain, stating: "This is where the soul resides."

Descartes noted that the brain is perfectly symmetrical, except for the pineal gland, which is unique and central. He deduced that it must be the place where dual sensory information (two eyes, two ears) unifies into a single conscious thought.

Today, science confirms its central role as a regulator (biological clock) and a neuro-endocrine interface.