Human nature is the concept that there are a set of characteristics, including ways of thinking, feeling and acting, that all 'normal' human beings have in common.
The soul is seen as the substantial form of the body (matter). The soul, as the substantial form, is what is universal, or common, to all humanity, and therefore, is indicative of human nature; that which differentiates one person from another is matter, which Aquinas refers to as the principle of individuation. The human soul is characterized as spiritual, immortal, substantial, and subsistent: it is the spiritual and vital principle of the human being, but is also dependent on the body in a variety of ways in order to possess these characteristics. Thus, no division is made between the "physical" and the "spiritual," though they are in fact distinct. This position differentiates Thomism from both materialism and idealism. Unlike idealism, it holds that the visible universe is not a mere shadow of a transcendent reality, but instead is fully real in and of itself.
人性的概念，有一组特征，包括
思维方式，感觉和行动，共同的所有的“正常”的人。
灵魂是身体的物质形式（物质）。灵魂，为物质形式，是普遍的，或是共同的，所有的人类，因此，象征着人性；，区分一个人从另一事，
阿奎那指的是个体化原则。人类的灵魂是不朽的，其精神实质，，和存在的：它是精神的和重要的人的原则，但也依赖于以各种方式为具有这些特征的身体。因此，不分是“物质”和“精神之间进行，尽管他们实际上是不同的。这个位置区分托马斯主义的唯物主义和唯心主义。不同于
理想主义，它认为宇宙是不是一个单纯的阴影，一个超越现实，而是完全真实的本身。