The Human being can be viewed from the outside and explained this way, but it also must be explained from the inside of a human being. Starting from the outside, we look at the human being with prescientific knowledge or common sense. What separates man from every other creature is his ability to think rationally. What man lacks in survival endowments such as long claws, fur, etc., man makes up for in his ability to know. Man can think and know that he thinks. Man can eat and know that he eats. Man can speak and know that he speaks. The human being is able to conquer and have dominion over the creatures and the world itself, because of this unique ability to know rationally. There are many different areas where the human being shows this separation of pure intellect. One would be his tool-making ability, or homo-faber. It is true that some monkeys can make tools, but it is only man that makes these tools not just as an extension of their bodily reach, but as a direct fruition of their thoughts. Community, Language, Science, Arts, Religion, Death, and Culture are all elements that show man’s rationality, his intellect. It is important to note that the human fact must be explained with a combination of two methodologies, the body/material side, and the soul/immaterial side.
We now move to the inner structure of man, the ontical, real structure of man. From inside, we can determine that the human being exists with two different manners of the subject, Mine. Firstly, there are external possessions which I call mine, in which in this case I see myself as the phenomenological I, or the center of the related outside things. There are also direct acts that relate to the human being, which one calls mine. These can be physiological such as my breathing or my walking, etc. There is also the psychical side, where I have my sensory and mental cognitive functions, as well as my appetitive functions.
This side brings us face to face with man’s intellect. The intellect exists via the soul and thus acts through it. St. Thomas Aquinas notes that the soul is that which forms the body. Because the body acts, the acts from the body can be attributed to the higher form of the soul. Aquinas also stated that the soul possesses its own act of existence, which it then imparts to the body. The soul is naturally immaterial and thus a subsistent form. The soul organizes the body. When the body is unorganized, this means the body does not exist. It is for this same reason we can say that the human being’s death, (or cease of bodily existence) does not mean that the soul of the same human being ceases to exist as well. The soul, as determined, is a subsistent element, that cannot be destroyed by the mere cessation of the body. The soul experiences the external world and has the possibility of self-cognition because it is expressed through the body. Existence belongs immediately to the soul, and only to the body exclusively through the soul.
Within the soul of a human being, there exists the intellect and the freewill. The intellect is concerned with the process of knowing the truth. Knowledge involves processing new data from what is real, from reality. When in the process of knowing, the first thing that the intellect grasps is existential judgement, meaning, does this exist or not exist? St Thomas Aquinas said that reality can be understood by 2 things: Existence and Essence. Existence is ‘the what’, or the being of the object. Essence is ‘the how’, or how the object is being (its attributes). Knowledge then is objective and can be defined as the understanding of a real, concrete thing under the aspect of a grasped meaning. The meaning which presents itself in consciousness is also subjected to the thing itself, thus keeping inside the lines of the Aristotelian system, where it is taught that we come to know cognitively our ideas and thoughts by the world acting on our senses.
The intellectual life can be broken down into three areas according to Aristotle: Theoria (contemplation for truth), Praxis (behavior or practical knowledge), and Poesis (productive activity for skills). St Thomas Aquinas also arranged these into three areas calling them Speculabile, Agibile, and Factibile.
From intellectual life, we can determine that there are 2 different types of knowledge that the human being searches for: Theoretical Informational knowledge, which according to Aristotle consists of Nous (perception of the first principles of being), Episteme (reasoning in its widest sense), and Sophia (wisdom), and Scientific Knowledge, which possesses these three elements – necessity, immutability, and universality.
The human being has the free will as the second power of its soul, and it is this element where the drama is set for man to decide between following the cultural influences, or the genetic (natural) influences. Much like how Knowledge aims for knowing the truth, Freewill of man aims for a particular, concrete good. The freedom of man to make a decision holds the aim of morality. Decision making involves three main phrases: Intention of the goal, Order of concrete action, and the order of execution. Within these phases, there are two types of practical judgments a human being makes. The first is a theoretically practical judgement or synderesis, which means that one knows that their action is good and coincides with the natural law. The second is practically- practical judgement or auto-determination, which decides whether to agree with the natural law and /or the divine law.
Thus, we can define a human being as a rational animal, a compositum of both body and soul. Its soul is the subsistent element, and its powers involve the knowing intellect and the will to do good. With freewill aiming toward good, and knowledge aiming towards the truth, the human being works towards becoming more beautiful in the sense of intentionality, of culture.