 Like some of his predecessors, Aristotle held that the elements Fire, Water, Air, and Earth were the building blocks of all substances. But unlike his predecessors, Aristotle established this list from fundamental principles. He argued that “it is impossible for the same thing to be hot and cold, or moist and dry … Fire is hot and dry, whereas Air is hot and moist …; and Water is cold and moist, while Earth is cold and dry” (DG II.3, 330a30–330b5). Aristotle supposed hot and moist to be maximal degrees of heat and humidity, and cold and dry to be minimal degrees. Non-elemental substances are characterized by intermediate degrees of the primary qualities of warmth and humidity.