The Four Causes One of the most important pillars of Aristotle’s philosophy was his theory of the four causes.
Whenever you want to know what something is, there are, basically, four questions you can ask about it:
What is it made of?
Where did it come from, or what produced it?
What kind of thing is it?
What is it for?
The answer to each of these Aristotle would call a cause of that thing. It’s a “cause” in the sense that it contributes to the existence of that thing as the sort of thing it is. The first question deals with the “formal cause,” the second the “material cause,” the third the “efficient cause,” and the fourth the “final cause.”
That’s a little abstract. Let’s use a concrete example. Take my guitar.
What is this thing made of? That is, what is its material cause? It’s made of wood, some metal and plastic, and metal strings. It would not be the thing it is if it weren’t made of these materials. In that sense, the materials are one of the causes of the existence of the thing.
What produced this thing? What is its efficient cause? If it were a hand-crafted guitar, the answer would be “a luthier” (that’s the technical name for a maker of guitars), but since it’s a big brand name, it probably was a combination of machines and people. Knowing what made it tells us something about the kind of thing it is.
What is it? What is its formal cause? It’s a guitar. Its arrangement of the various components into this particular shape and structure make it a guitar. You could have the different parts (neck, body, strings, headstock, etc.) all glued together in the wrong configuration, but that wouldn’t make it a guitar. The very form of “guitar-ness,” in that sense, is one of the causes of its existence: if not for the form of guitar, this thing would not be a guitar.
What is it for? What is its final cause? A guitar is for playing music. It is not for chopping down trees or brushing your teeth. If it weren’t for the purpose of playing music, the guitar would not be a guitar.
It may sound a little foreign to you that a thing’s purpose or its materials could be the cause of its being in any way. Modern science has reduced “cause” to the “efficient cause”: what brings it about? This is because the efficient cause is the only one that falls within the scope of empirical science’s method of investigation. You can’t test for the final cause or formal cause of a thing in a lab. You could determine a thing’s component materials in a lab, but from science’s point of view they would be mere building blocks, inactive and manipulated. The other three causes are philosophical principles, not scientifically verifiable phenomena. But that doesn’t make them any less real. The four causes are extremely useful for defining things. By identifying the four causes for a thing, you can get a pretty good picture of what it is. So, if I say, “A table is a piece of furniture made by a carpenter or machine out of a sturdy material for the purpose of holding other items at a certain height.” Now, if you’d never encountered a table before, you’d have a fairly good idea of what it was.
Aristotle’s four causes come up A LOT, not only in his philosophy, but in the later philosophy and theology of those, like St. Thomas Aquinas, who used Aristotle’s philosophy as a framework. Even in Aristotle’s work on poetics he uses them to define literary art! Point is: it’s super useful. Give it a try.