According to Aristotle, humans ought to aim for a flourishing life which a good human would have and in order to determine human goodness, we need to understand the function of humans. Aristotle believes that rational activity and rationally guided cognition is the human function. Rationality is essentially acting in ways that are in accordance with reasons and to do that is by fulfilling the virtues that are correspond with the characteristic function. Aristotle uses the function of an object and connects that to finding the function of humans and how we can fulfill that function well. The purpose of the Function argument is to understand what human beings are, what their function is, and how cultivating virtues accomplishes a flourishing life for humans.
The characteristic activity of a thing is the same as that of a good thing of the same type.
If we take the characteristic activity of a human to be living of a certain kind of life, then we can see the difference between a human and a good human that have the same characteristic activity is that the good human is the one that lives that life well.
Taking characteristic function of a human to be activity of the soul in accordance with reason, then the activity of a good human being will to be to carry out this function well.
In order to carry out this function well, one must do so according to certain virtues, the virtues relevant to one’s characteristic function.
For a human to perform their function well, they must do so in accordance with the human virtues, the virtues of acting in accordance with reason.
Aristotle thinks that if we can determine the what the human function is, then in the same way we determine the characteristic function of an artifact, we could understand what it is to be a good human. The premises define the function of humans which helps determine the goodness of an individual. Premise 1 and 4 can be applied to animals and/or plants and premise 1 is true because what makes the thing good is how well it is at performing its characteristic function. Artifacts, man made objects, have characteristics functions and are judged based on that function. For example, the purpose of a knife is to cut things and typically, a good knife needs to be sharp because by being sharp, the knife will cut more efficiently. Another example: a good car must be good at transporting and a bad car would break down and not fulfill its function, however, a car is still a car despite how effective it is at transportation. This concept leads into the second and third premises which help us understand what human beings are and what our function is. The second premise distinguishes the difference between a regular human and good human by focusing on how they live their life when they have the same characteristic activity. Regular humans and good humans don’t differ in our function. The third premise distinguishes humans from other life forms and points out the type of life that is characteristically human. The human characteristic function isn’t just to live and survive because plants do that as well, sentience distinguishes humans from plants and sapience distinguishes humans from animals. Sapience is rationally guided cognition. According to Aristotle, human function is activity of the soul that follows a rational principle. He defines the soul as the human psyche or cognitive faculty and the rational principle as non-instinctive and based on reason. An example of sapience or rationality present in humans is the cat that cannot make the rational decision of doing the things it wants to do outside when it’s outside and then coming inside. Instead, the cat goes in and out of the house repeatedly. Premise 3 sets up premise 4 which answers what must be done to fulfill characteristic functions well. Characteristic functions come with virtues and in order to serve our function well, we must be in accordance with the virtues. Premise 4 is a little more generalized that introduces the ideas of virtues which are excellences or properties that give the thing the ability to perform its characteristic function well. Going back to the knife example, a possible virtue of the knife would be its sharpness because it allows it to cut well. This directly relates the virtue or feature and its characteristic function. Premise 4 has given premise 5 the opportunity to specify how a human can act in accordance to reason and rationality which is through human virtues. Some of those virtues may be courage, temperance, generosity, etc. Virtues that humans need to develop are virtues that allow them to use their rational cognition; a good human would have cultivated more virtues whereas the regular human would not have. A good human is to reason well and follow through with those reasons and not purely follow your instincts. Aristotle believes that character is what makes a good person which is determined on the practical virtues and that humans have a rational soul which allows them to achieve those moral virtues.
The function argument alludes that everything has a function and by that claim, humans also have a function which the premises break down and elaborate on the human function and how humans may achieve the end goal of living a flourishing life. Aristotle’s argument works beca The argument uses premise 1 as a way to present the plausible concept that everything has a characteristic function and by performing its characteristic function well is what makes it good. Premise 2 then connects human life to our characteristic activity and partly helps us understand what humans are. Premise 3 separates humans from other living beings and introduces the human function which is rationality. Premise 4 takes a step back and examines how things go about fulfilling their function which is by cultivating virtues. Premise 5 then concludes the entire argument by relating all the premises back to humans and connects virtues that humans must cultivate in accordance with reason to obtain a flourishing life, something a good human ought to strive for.