Philosophical anthropology, sometimes called anthropological philosophy, is a discipline dealing with questions of metaphysics and phenomenology of the human person, and interpersonal relationships. Augustine of Hippo was one of the first Christian ancient Latin authors with a very clear anthropological vision, although it is not clear if he had any influence on Max Scheler, the founder of philosophical anthropology as an independent discipline, nor on any of the major philosophers that followed him. Augustine has been cited by Husserl and Heidegger as one of the early writers to inquire on time-consciousness and the role of seeing in the feeling of 'Being-in-the-world'. Augustine saw the human being as a perfect unity of two substances: soul and body. He was much closer in this anthropological view to Aristotle than to Plato. In his late treatise On Care to Be Had for the Dead sec. 5 (420 CE) he insisted that the body is essential part of the human person: Augustine's favourite figure to describe body-soul unity is marriage: caro tua, coniux tua – your body is your wife. Initially, the two elements were in perfect harmony. After the fall of humanity they are now experiencing dramatic combat between one another. They are two categorically different things: the body is a three-dimensional object composed of the four elements, whereas the soul has no spatial dimensions. Soul is a kind of substance, participating in reason, fit for ruling the body. Augustine was not preoccupied, as Plato and Descartes were, with going too much into detail in his efforts to explain the metaphysics of the soul-body union. It sufficed for him to admit that they were metaphysically distinct. To be a human is to be a composite of soul and body, and that the soul is superior to the body. The latter statement is grounded in his hierarchical classification of things into those that merely exist, those that exist and live, and those that exist, live, and have intelligence or reason. According to N. Blasquez, Augustine's dualism of substances of the body and soul doesn't stop him from seeing the unity of body and soul as a substance itself. Following Aristotle and other ancient philosophers, he defined man as a rational mortal animal – animal rationale mortale. Philosophical anthropology as a kind of thought, before it was founded as a distinct philosophical discipline in the 1920s, emerged as post-medieval thought striving for emancipation from Christian religion and Aristotelic tradition. The origin of this liberation, characteristic of modernity, has been the Cartesian skepticism formulated by Descartes in the first two of his Meditations on First Philosophy (1641). Immanuel Kant (1724–1804) taught the first lectures on anthropology in the European academic world. He specifically developed a conception of pragmatic anthropology, according to which the human being is studied as a free agent. At the same time, he conceived of his anthropology as an empirical, not a strictly philosophical discipline. Both his philosophical and his anthropological work has been one of the influences in the field during the 19th and 20th century. After Kant, Ludwig Feuerbach is sometimes considered the next most important influence and founder of anthropological philosophy.