For example, when we look at an orange, we analyze the particular orange and a universal form of an orange. Moreover, when we place the orange near a plate, we speak of both of them been next to each other. Furthermore, he also argued the existence of “unistantiated universals”. These are universal forms that do not relate to a particular thing. When we speak that there is a particular good in existence, for example, then “good” can be referred as proper universal form (Melchert, 28). However, Aristotle challenged Plato’s argument that the nature of universals is instantiated. He argued that all universals are attached to existing things. Aristotle believed that the nature of universal can be predicted. This is because universal only exist its relation must have occurred, is occurring or must occur in the future. Hence if a universal cannot be predicted to an object that occurred in a certain period, it cannot exist. He also maintained universal location exist within each thing on which it existed. So, according to him, the form of an orange exists within each orange, rather in the world of oranges (Melchert, 35). Teleology is a philosophical explanation that explains the fact that the final causes do exist in nature. This theory put across the assumption that human action and is existing factors in the nature of the environment (Melchert, 123). Generally, this theory explains the purpose, end, aim and goal of the existence of something. Aristotle explained this theory by arguing that without artificial interference, an action will happen as stipulated by the natural forces affecting it. An example put across by Aristotle states that a seedling reaches to a level of the adult plant as its final cause. While explaining his metaphysics, Aristotle always argued that the final cause of an action or an object is already stipulated by nature and no force can change this outcome. Through teleology his argument on final causes were further explained. Additionally, Aristotle has argued against many philosophers claims that all things revolve around the necessity. By this statement Aristotle believed that the philosophers were against the purpose, end, aim and goal policy of teleology (Melchert, 112). Descartes was a philosopher. He developed the “Descartes Model of the Mind”. He argued that the mind could only recognize ideas. This was of great concern to him as he tried to show that the mind is only a perceive receiver as argued by Melchert (43). Hum on the other hand disapproved Descartes’ work. Hum argued that Descartes did not clearly characterize the cause and effect of ideas. According to him, there is no logical connection between cause and effect. For example if one looks at a broken flask on the floor, they are two separate ideas generated. In referring to Melchert induction is the act of justifying ones reasoning (77). Hum rarely used the term in his work. He only used it to justify some points he was making. Hum’s philosophy argued induction is the cause of casual relations and not reasoning. He also pondered on the justification of induction. Hum argues that induction must be valid. He challenged other philosophers to come up connections for their reasoning. The argument of induction by Hum is the current method used by philosophers to argue their work. Descartes believed that God was the cause of every perfect thing. This was the only logical explanation he could find to explain the nature of things. Descartes believed in himself and his feelings. This was due to the fact he was sure that God could not deceive him. He could not understand how other philosophers argued of subjects but not stating their origins. However, this did not go down well with Hum.