The word spirit comes from the Latin spiritus, which is a translation of the Greek pneuma, meaning “breath.” Around the thirteenth century, the term became entangled with beliefs about immaterial souls, supernatural beings, ghosts, and so forth. It acquired other meanings as well: We speak of the spirit of a thing as its most essential principle or of certain volatile substances and liquors as spirits. Nevertheless, many nonbelievers now consider all things “spiritual” to be contaminated by medieval superstition.
