Aristotle’s philosophy is not only empirical, but is also so fundamentally influenced by the biological sciences that we can best characterize his philosophy as organicist. Aristotle examines not only biological life with a view to the purposiveness of nature, but all other objects as well as human meaning and human institutions. A part of his focus is always on functions or purposes.
While Aristotle does accept and develop the earlier developed elemental views of the Ionian philosophers, arguing that all things are comprised of fire, air, water, and earth, the focus of his approach is not on what might be characterized as the mechanical workings of such elements. Rather the main components of the world that he investigates are substances. All objects in the world are substances: and these are understood as combining matter and form. In counter-distinction to Plato, Aristotle does not think that forms exist independently of particular objects. He rejects the view of a Platonic separate world of forms and argues instead that all objects always combine matter in a particular shape or form. Yet if we want to understand these substances it is not enough to understand this alone. We must also comprehend the origin of the object, as well as its purpose or function. This roughly outlines Aristotle’s view of what become known as the four causes: the material, formal, efficient, and final causes. In order to understand specific objects, in accordance with this teaching of the causes, (1) we must comprehend what they are made of, the stuff that comprises them — that is, their material cause; (2) the form or structure in which this stuff is shaped — that is, their formal cause; (3) the origin or creator of the substances — that is, their efficient cause; and (4) the purpose or function of the thing, what it is for — its final cause.
To take a wooden, hand-crafted table as an example: The material cause is the wood of which the table is made. The formal cause is the shape into which the wood is formed, its table form. The efficient cause is the carpenter who made it. The final cause is to facilitate dining in relative comfort. There is of course some variability in human made objects. Might the table be a desk if used more for writing than for eating? Natural substances, rather than man-made ones, lack such variability.
Aristotle further understands substances in reference to processes. Here the concepts of potentiality and actuality are of primary importance. A given material, like wood, in the form of a tree, may have the potential to be shaped into different forms. Chopping down the tree one can then use the lumber to create a chair or a table or a desk. The material has potential to assume varying shapes, which then facilitate varying purposes. For human-built objects, it is the human being that decides what form a particular material should take and what purposes it will serve. But Aristotle also thinks that these concepts of potentiality and actuality are important for natural objects. The acorn has the potential to become a full-fledged oak tree. What we would today recognize as its DNA sets that acorn on a particular trajectory of development so that under the right conditions of receiving water and minerals from the earth it will become a more or less thriving oak tree. Aristotle did not have access to terms like DNA or chromosomal structure that we can use today to describe what contemporary biologists refer to as “teleonomy,” but he is trying with less impressive and empirically supportable concepts to describe a similar development. The form is the essence of the object. It allows the material development in a particular manner toward a specific goal. The efficient cause of the acorn is the parent tree.
Aristotle’s ethics can also be fruitfully understood in reference to these four causes. A particular human, like Socrates, is particularly structured mass of bones and flesh, specifically one with a human essence or form. The efficient cause are the parents. The final cause is the purpose for which humans live. As “rational animals” and “social animals” Aristotle argues our purpose consists in fulfilling our rational and animal natures. We will need a proper mix of what can be called external goods, like food, health, water, friends — things that other social animals would need — and internal goods, specifically the intellectual and character virtues that fulfill our rational natures.
The polity too can be understood in terms of Aristotle’s four causes. It is a grouping of individuals (its material cause) in the form of its particular constitution (it formal cause), which provide its structure. It is created by the will of those individuals that comprise it (its efficient cause). Finally its purpose, in Aristotle’s view is to facilitate humans in achieving their natural purposes — namely in achieving the external and internal goods noted above.
While Aristotle’s application of teleology in physics has generally been rejected, the teleological view of natural organisms has still been generally retained, even if scientists might prefer the term “teleonomy” instead. In reference to human-built objects, including polities, it is not particularly problematic, although the ascription of “natural” purposes rather than human ascribed ones for such objects or entities is extraordinarily strongly contested. Today, many in political theory would ask instead what purposes we intend the state to have or what purposes we want to give to our own lives. Nonetheless, there are various natural law or anthropologically based positions in ethics and politics that focus on the fulfillment of human needs as primary. Aristotle’s views, especially as applied to ethics and politics, have been fruitfully reinterpreted for different ages, with different concerns and different background understandings of metaphysics — from the 13th century Christian interpretations by Aquinas to the 19th century ones by Hegel to 20th and 21st century variations on Aristotelian themes by Hans Georg Gadamer, Aldasair McIntire, or Martha Nussbaum and Amartya Sen and others still.