Aristotle (384-322 BC) made four decisive contributions to philosophy. First, in metaphysics, he refuted Plato’s theory of forms. While Plato had believed in a world of pure abstractions (which he called “forms”), Aristotle emphasised observing the material world. Second, Aristotle came up with the concepts of substance and form. He asserted that each item is composed of substance and form. Substance refers to its underlying essence, and form to its individual characteristics. The combination of substance and form define the identity of each entity or person. Identity determines how an entity will behave, its present and future actions. Those are connected by relations of cause and effect, which constitute Aristotle’s theory of causality. Aristotle studied motion and defined four types of causation (material cause, formal cause, efficient cause, and final cause). The latter (final cause or purpose) is crucial for understanding human motivation and behaviour. Third, Aristotle reinvented morality in his “Nicomachean Ethics.” He argued that the goal of human life is “eudaimonia” (happiness, flourishing, thriving, fulfilment) and that the path to eudaimonia requires a virtuous life. Aristotle’s view of virtue is linked to individual happiness, not to supernatural edicts. He came up with a new art theory in his work “Poetics” and identified objective criteria for telling apart good from bad art, explaining the link between art and happiness. Fourth, in his work “Politics,” Aristotle examined all forms of government (monarchy, aristocracy, polity) and the risks of corruption that transform them into tyranny, oligarchy and mob rule. He favoured a mixed form of government where power is divided amongst the monarch, the aristocracy, and the people. Let us explore these four key contributions, one by one. Aristotle refuted once and for all the theory of forms devised by Plato (428-347). Plato had conveyed his philosophy through his dialogues (a literary genre) where Socrates is often the main character. The key element of Plato’s philosophy is the theory of forms or theory of pure abstractions. Plato believed that the world we perceive is just an imperfect reflection of an intangible world made of pure abstractions or “forms.” According to Plato, the acquisition of knowledge consists of accessing the world of forms. Plato stated that most people live in a state of ignorance, like prisoners in a cave, perceiving only shadows of a true reality, which can only be accessed through education about the forms. Aristotle’s greatest contribution was to discard the theory of the forms. We learn through observation and thinking, he said, not by mystical connection to a world of pure abstractions. You should look at reality, study the characteristics of entities, and figure out how they are interconnected through causality. Here is the link to the original article: https://johnvespasian.com/aristotles-four-key-contributions-to-philosophy/