‘Physics’, for Aristotle, is essentially the study of things which change in space and time. The only things that are not ‘physical’ in this sense are unchanging essences (math, logic) and God (which for Aristotle was an ‘unchanging substance’.). God is included in the Physics Book VIII because of its role in explaining eternal physical motion, not because it is physical in itself. On this view, anything that changes through time is part of “physics”. IN algebra, adding x to y to get z is a ‘change’ in a sense, but it’s not taking place in time, so it’s not ‘physical’. Rocks, planets, stars, the weather, atoms, light, lightning, etc. are all physical because they change in time.
Living things are also ‘physical’ in Aristotle’s sense; they have every attribute that any other physical thing has: mass, energy, size, et cetera. However, they also have other things that nonliving physical objects do not have: heredity, metabolism, adaptation, function, ecological niche, genome, genotype, phenotype, et cetera.
These are very interesting and surprising characteristics that you could not predict from physical characteristics, so many people are tempted to say that there is something nonphysical about life. This intuition is nearly universal among traditional beliefs and in “vitalism”. Vitalism was taken seriously by Aristotle and many other scientists up until the early 20th century, but no longer. However, it is still a fact that biological properties are different in meaning from physical properties, so in philosophy some people try to make this seem like some fatal flaw in physicalism. However, every such criticism cannot get around the fact that every biological fact is “superveninent” on the physical. This means that you cannot change a biological fact without changing a physical fact., and conversely the only way to change a biological fact is to change some physical fact. Life may of may not be ‘reducible to physics (whatever that means), but there is nothing supernatural about life; it breaks no physical laws and it is implemented only by physical laws. Biology is perhaps just a shorthand that simplifies the expression of certain things that certain physical objects do.
Just as “physics” has the subfield of biology, so also Aristotelian biology has a further subfield: ethics . According to Aristotle, “ethics” is the study of a certain subset of living creatures which “have logos” and are “political”. Neither of these terms have a simple translation from Greek into English. But in my view it means those animals which can:
- Live in a society.
- Be “responsible”, which means:
- Be held responsible for one’s actions by others.
- Accept responsibility from others for one’s own actions.
- Hold others responsible for their actions.
- Have character (behavioral tendencies).
- Perhaps many others….
All of these above processes are changes which take place in time, and which can only be done by particular kinds of living creatures. In any case, there is no way that ethics could possibly be relevant to any non-physical being without engaging in fantastic speculations that contradict ancient and modern physics. For Aristotle, the ‘soul’ was defined as a principle of change in living creatures, and not as anything ‘supernatural’ or having anything to do with an afterlife. Ethics was thus defined as a subfield of “physics”, the study of the principles of change in nature.
The famous ‘Four Causes’ apply within ethics just as they do in every other subfield of “physics”. Perhaps there are some differences in how they are used, but they apply. As such, Aristotle’s “Physics” can be seen as a foundation for his Ethics. It is certainly a foundation for my adaptation of his ethics to our modern world. The biggest change that we see in the modern world is that only biology and ethics have final causes, whereas nonliving physics does not. This is not a very contraversial thing to say nowadays, and it leaves the validity of final causes in biology and physics intact. Biology cannot get along at all without final causes, because without final causes you could not say “birds should be able to fly” or “the immune system should retain antigens from previous pathogens” or “the temperature of the earth should allow for liquid water”. Of course each of these statements makes some assumptions to be true, but they are all naturalistically meaningful and decidable. Furthermore, if ethics is a subfield of biology, then it must also have final causes, and they must work in a similar way. Just as birds should fly, humans should be able to talk and cooperate to satisfy their mutual needs in an efficient manner. While some ants rely on slavery exclusively, humans tend to rely on voluntary cooperation, and in both cases the ultimate causes are those common to all living creatures. And as time goes on, slavery is losing out to voluntary systems and this trend is is the basis for the ethical statement “Slavery is wrong.” It could have been the case that slavery was more adaptive than freedom, but as it turns out this is not true.
Modern physics also includes everything we need to explain ethics, since all living creatures follow the physics of information. All life is just information processing; evolution itself as well as the behavior of living creatures are all essentially forms of information processing. This means that without information processing, there can be no life and vice versa, because they ultimately mean the same thing.
So what is the upshot for our current situation? Obviously Aristotle’s Physics as he has presented it cannot be accepted, so are all the above irrelevant to us? No, In my opinion the teleological aspect of Aristotle’s Physics has been merely “demoted” down to biology, which is where it was really suitable in the first place. Aristotle saw that final causes were ubiquitous in biology, so he assumed that this was true of the rest of ‘physics’ as well. But in the modern world, we know that final causes originated with life and are meaningless apart from life. Since we know that physics preceded biology, the sun is not ‘for’ the Earth’s biosphere in the robust sense that Aristotle and Classical Theism have in mind. Rather, the teleological aspect is emergent from the behavior of certain molecules in certain conditions.
The applicability of Aristotelian teleology is limited to the results of evolution, the biosphere, and the inputs necessary for life. Ethics falls within this sphere, and as such Aristotelian final causes are applicable. The final causes are the same as those defined by evolution: not going extinct, also known as “inclusive fitness”, the passing on of DNA. That’s what ethics is for: promoting forms of cooperation which pass on DNA. Something like this view is or should be the default view, since it assumes that the behavior of a certain organism has an evolutionary origin. This axiom is assumed in the study of all other organism besides humans, and the world will not end if you try out this assumption on one more creature.
If you disagree with this, please leave a comment telling the rest of us what ethics is for. While you formulate your answer, ask yourself is your alternative really the sort of thing that could be the founding theory of a branch of natural science? Because that is what ethics is. The only other conception that makes any sense is the Platonic and Kantian conception of ethics as a formal or exact science. This theory cannot be dismissed out of hand, but on my view all the aspects of ethics that support Platonism are most parsimoniously seen as deriving from the most general axioms of evolutionary game theory, which even in their general form are imperatives followed for a purpose.