by Jason Stotts
Aristotle develops the idea of the “four causes” in his Physics (III.3.194b16) and Metaphysics (I.3; II; V.1,2; ). The four causes are: Efficient (“the primary source of change or rest”), Material (“that out of which a thing comes to be”), Formal (“the form or the archetype”), Final (the “end or that for the sake of which a thing is done”). Aristotle maintains that understanding these causes is necessary to truly understand a thing.
Although Aristotle does apply these to humans in De Anima, the Nicomachean Ethics, and the Eudemian Ethics (among others), it is clear that he primarily uses them to explain non-human existents. For example, the two most famous examples in Aristotle’s writings are of the bronze sphere and the Oak tree. In each example, he elaborates the four causes with respect to each of these. However, this does not mean that he does not apply them to humans as well.
When we think about humans, the four causes become somewhat more complicated. The material cause is easy: we have animal bodies made up of muscle, fat, bones, etc. The formal cause is slightly more complicated, but not that hard: our DNA codes for a particular type of being and we may say the the resultant distinct “humanness” is our soul (in the Aristotelian tradition, not in the perverted Platonic tradition that christians follow). But what about the efficient cause? Can we really look at the chemical reactions in our brains as the source of our movement? No, the efficient cause in humans is our mind’s ability to understand the world around us, to understand possibilities and potentials, to evaluate ends, and then to will action. We are our own efficient causes.
The greatest problem with applying the four causes to humans, though, is the final cause. Indeed, if we are being rash we may jump to the conclusion that our final cause is in our DNA and outside or our control. However, this would be impertinent. While my DNA is responsible for laying the blueprint my body follows in developing, it hardly forces me to be human. Before me pursue this, let us look to the example of the Oak tree we moved past above. The telos of an acorn is a full mature Oak tree. The acorn has no control over whether or not it will be an Oak tree one day, if the situation is advantageous, then the acorn will develop correctly. If the situation is not, then it will not develop correctly. Importantly, the acorn has no control over whether or not it will ever develop into a large majestic Oak. Humans, on the other hand, have control over the course of our lives. We can choose to exercise our distinctly human faculties or we can choose not to (we cannot, however, choose not to choose). This complicates matters as it means that our efficient cause (our reason and will) can be directly responsible for the actualization of our final cause (developing into a full mature adult human).
Even worse, though, is that our final cause is not a foregone conclusion as it is in the case of the acorn and Oak. We are not born knowing what it means to develop into a full mature adult human and if we do not work at learning what this means, then we may never so develop. Consequently, it is imperative for humans to study our final cause and how to best develop our distinctly human faculties.
In order to do this involves inquiry into what is called metaphysical biology in the Aristotelian tradition or philosophy of personhood in general. The whole object is to understand human nature and what our final cause might look like. It is, in fact, a precondition of any system of Ethics to understand human nature as if the object of the inquiry is not understand, the inquiry can never hope to come to fruition.
I point this out because it is all too common to miss this and begin an inquiry into human action (Ethics) without understanding human nature. This, I think, is one of the major causes of the failures of Ethics in any history of Ethics, whether Western or not.