Kūkai's exposition of what has been called Shingon's "metaphysics" is based on the three aspects of the cosmic truth or Hosshin – body, appearance and function. The body is the physical and mental elements, which are the body and mind of the cosmic Buddha and which is also empty (Shunyata). The physical universe for Shingon contains the interconnected mental and physical events. The appearance aspect is the form of the world, which appears as mandalas of interconnected realms and is depicted in mandala art such as the Womb Realm mandala. The function is the movement and change which happens in the world, which includes change in forms, sounds and thought. These forms, sounds and thoughts are expressed by the Shingon practitioner in various rituals and tantric practices which allow them to connect with and inter-resonate with Dainichi and hence attain liberation here and now.