Complex sentence: Prima materia, materia prima or first matter, according to alchemists, is the starting material for their magnum opus and the creation of the philosopher's stone.Exoterically it is the primitive formless base of all matter similar to chaos, the quintessence, or aether.
Split into simpler sentences: Prima materia, materia prima or first matter, according to alchemists, is the starting material for their magnum opus and the creation of the philosopher's stone. It can be expressed exoterically as the primitive formless base of all matter similar to chaos, the quintessence, or aether.