Temperature, material elements, chemistry, and stability, all of these things play their part.

温度、物质元素、化学成分、稳定性，这些都在人类存在中扮演着重要的角色。

Again, he was the first to speak of four material elements; yet he does not use four, but treats them as two only; he treats fire by itself, and its opposite-earth, air, and water-as one kind of thing.

再一次，他是第一个谈到四种物质元素的人；却不用四，只当二。他将火本身及其对立面——土、空气和水——视为一种事物。