What is aristotelianism?

Aristotelianism is the philosophy/worldview of Aristotle, a 4th century BCE philosopher from Macedonia who taught at a school in Athens, Greece. Aristotle was what in that time would have been considered a scientist, examining and analyzing the various phenomena of the natural world, biological life in particular. He was a student of Plato. He conceptually analyzed every particular entity in the world into 4 "causes" or aspects: the material cause (what the entity is made of), the formal cause (how the material is arranged and behaves), the agent cause (what forms the raw material into the formed material which is the entity), and the final cause (what the entity acts towards; the entity's goal). The first and third causes mentioned above Aristotle derived from earlier philosophers and the formal cause he modified from his teacher Plato's conception to be less abstract to be understood only as an aspect of an entity rather than a self-existent non-material entity itself. The final cause was largely Aristotle's own contribution to philosophy and was no doubt influenced by Aristotle's study of biological life with the animals' various parts working in tandem for some common purpose. The above causes that I mentioned are elements of Aristotle's Metaphysics, his investigation into the most fundamental elements/structures of the world of our experience. He also wrote his Physics, which is his analysis of entities in motion; his Logic, his analysis of the categories and concepts by which we process and speak about the world; his Psychology; and his Ethics.

Aristotelianism today applies mostly to the systematic investigation and articulation, begun by Aristotle, of Metaphysics, Logic, and Ethics but is more of a way of understanding the world in broad or general strokes aided as much as possible by the results of the empirio-metric sciences. It may well be argued that Aristotle's notions of substantial forms and final causes are outside of the scope of empirio-metric science, that is to say they are not measurable, but they are nonetheless valid and universal observations which are best developed by means of careful reasoning.