A grasp of Thomas's psychology is essential for understanding his beliefs around the afterlife and resurrection. Thomas, following Church doctrine, accepts that the soul continues to exist after the death of the body. Because he accepts that the soul is the form of the body, then he also must believe that the human being, like all material things, is form-matter composite. Substantial form (the human soul) configures prime matter (the physical body) and is the form by which a material composite belongs to that species it does; in the case of human beings, that species is rational animal. So, a human being is a matter-form composite that is organized to be a rational animal. Matter cannot exist without being configured by form, but form can exist without matter—which allows for the separation of soul from body. Thomas says that the soul shares in the material and spiritual worlds, and so has some features of matter and other, immaterial, features (such as access to universals). The human soul is different from other material and spiritual things; it is created by God, but also only comes into existence in the material body.