Soul: the animating and vital principle in humans, credited with the faculties of thought, action, and emotion, and often conceived as an immaterial entity (The American Heritage Dictionary of the English Language).

Brain: the portion of the vertebrate central nervous system that is enclosed within the cranium, continuous with the spinal cord, and composed of gray matter and white matter. It is the primary center for the regulation and control of bodily activities, receiving and interpreting sensory impulses, and transmitting information to the muscles and body organs. It is also the seat of consciousness, thought, memory, and emotion (The American Heritage Dictionary of the English Language).

“Meter means measure,” said Pantalaimon. “Like thermometer.”

—THE GOLDEN COMPASS (70)

Since mankind first postulated that humans possessed souls, one troubling question has captivated scientists and philosophers alike:

If humans do indeed have souls, where are they?

Do they have a meter? A measure, as Lyra’s dæmon, Pan, defines the term in Philip Pullman’s The Golden Compass? Can they be snipped and clipped and rearranged like livers, hearts, or elbows? What about sliced, frozen, or preserved? Can a soul be excised from its body, as Mrs. Coulter and the General Oblation Board believe?

If people have this mysterious bit of animating, vital principle, where in the complex human body does it reside?

Before the sixth century, philosophers and scientists such as Aristotle argued that the soul must be in the heart, the blood, or in bodily fluids such as phlegm  …