Ancient philosopher Aristotle was one of the greatest minds of Classical Greece, and his work set a precedent for how to conduct philosophy and what to expect from it. He believed that eternal truths were accessible in all things, and that reason must be used to reveal them. This approach to understanding helped him make elaborate progress in numerous fields of study, and future thinkers upheld this same emphasis on reason to expound some of the most complex problems in philosophy.
One of the most important concepts in Aristotle’s worldview and philosophical work is teleology. This is the idea that everything which exists has a particular function and progresses towards a higher good. Aristotle’s perspective directly contrasted that of his teacher Plato, whose philosophy proposed the existence of a metaphysical realm of ideal forms which determines how everything in the real world appears to us.
Aristotle inverts this dynamic; instead of ideal forms acting upon or moving towards us, all things are moving towards these ideal forms, whether that be the form of a perfect man or oak tree or abstract ideals like beauty or justice. This distinction is crucial because it legitimizes the knowledge we can obtain from studying the material world, tearing down Plato’s barrier between appearances and reality.
Man as the Rational Animal
It was Aristotle who first defined the human as the rational animal. Since then it has been widely accepted that the capacity for reason is what distinguishes humans from all other animals. Even though humans have bodily needs for survival, which we share with all animals, humans are naturally curious, possess a unique set of intellectual and social needs, and are always functioning to meet them. Aristotle’s word for the sole end exclusive to yet ubiquitous throughout human action was “eudaimonia”, understood as wellbeing or happiness and the unifying virtue in his ethical theory.
Get the latest articles delivered to your inboxSign up to our Free Weekly Newsletter
Aristotle maintained a rational approach in all his areas of study; he understood that the function of all things can become clear through observation, and that the function of any being or object is linked to its essence. Since humans are essentially rational, we can use reason to figure out how to best meet our own intellectual and social needs. Not only does this mean rationally determining how to live or act virtuously, which directly influences how to structure political systems, but also distinguishing good plays, art, and narratives from bad ones based on how well they reflect the human condition.
Aristotle had this same approach towards the natural sciences. He is considered the father of biology for his work analyzing the natural world and categorizing animal species. This endeavor also led him to develop a formal system of logic which, like his biology, stood unrevised for centuries.
Reason’s Resurgence in The Enlightenment
After the end of antiquity, the work of intellectual figures from that time like Aristotle were largely influential as more attention went towards the arts and sciences during the Renaissance and into the Enlightenment. While the teleological vision Aristotle had eventually phased out of the natural sciences, it was still confidently believed that reason was able to lead humans to uncover eternal truths. René Descartes, the first major rationalist philosopher of the Enlightenment, sought to use reason alone to prove the existence of God and the soul.
Other empiricist philosophers during the Enlightenment like John Locke and David Hume believed that what we learn is learned through experience, and worked to elucidate the limits of human understanding as reason comes into conflict with desires and the real world.
Categories of Being, Categories of Perception
Perhaps the most intriguing connection between Aristotle and Western thought at this time has to do with ontology, or what Aristotle called first philosophy. Since Aristotle was a realist, he believed that anything which was logically true must also have a corresponding structure that exists in the real world. He came up with ten categories that can describe what is observable about an object in the real world which also necessarily describe how that object exists in itself. It isn’t until Immanuel Kant, whose body of work synthesizes and reconciles the conflicts between the rationalist and empiricist philosophies before him, that we find an alternative scheme of categorization.
Kant devised a table of twelve logical judgements—observations that we make through perception or experience—and connects to it a table of twelve categories of understanding, basically rules of how the mind comprehends the world around it. This is one of the fundamental building blocks to Kant’s transcendental idealism, a theory that challenged the general tradition of Western philosophy up to this point. Instead of understanding the mind as a recipient of truth and knowledge, Kant describes the mind as a tool which projects explanations onto the world according to its own principles. This is a major rejection of Aristotle’s own conviction that humans are capable of truly knowing the nature of an object in itself, and it amplifies doubts over whether we can prove the existence of anything at all.