“气”所赋予或影响的人的本性，与“天命之性”或“天地之性”相对。“气质之性”包含两种不同的含义：其一，指“气”赋予人的禀性。或指人的刚柔缓急的性格，或指贤愚等具有道德含义的品格。这个意义上的“气质之性”与“天命之性”共同构成了人天生所具的本性。其二，指“天理”与“气”共同影响的人性。“天理”落入有形的身体之中就会受到“气”的影响。“天理”所赋予的道德本性与身体的欲求交错在一起，即是“气质之性”。

The moral characters of humans endowed or influenced by qi (气) stand in contrast with "heavenly endowed characters" or the "properties of heaven and earth." The term encompasses two meanings. First, it refers to the specific disposition of a person under the influence of qi, such as firmness and gentleness, patience and impatience, and wisdom and stupidity. Biased and unkind behaviors of people originate from the "properties of qi." In this sense, the "properties of qi" and the "properties of heaven and earth" together constitute a person's inborn character. Second, it means that heavenly laws and qi together influence a person's character. As heavenly laws are imbedded in the physical human body, they are influenced by qi. The interaction of moral characters endowed by heavenly laws and human desires reflects the properties of qi (vital force).

引例 Citations：

◎形而后有气质之性，善反之则天地之性存焉。（张载《正蒙•诚明》）

事物凝聚成形以后就禀受了气质之性，善于复归本原则天地之性得以实现。

Physical matters take up their shape which acquires the nature of qi (vital force); if we are thus good at returning to it, then the nature endowed by heaven and earth will be preserved. (Zhang Zai: Enlightenment Through Confucian Teachings)

◎论天地之性，则专指理言；论气质之性，则以理与气杂而言之。（《朱子语类》卷四）

论说天地之性，则是专门就天理而言的；论说气质之性，则是就天理与气混合一体而言的。

As for the properties of heaven and earth, they refer exclusively to heavenly laws. As for the nature of qi, it refers to the combination of heavenly laws and qi. (Classified Conversations of Master Zhu Xi)

（推荐：教育部 国家语委 供稿：北京外国语大学 外语教学与研究出版社）