Dear Lorraine
> I think the word "purpose" is being used in at least 3 senses:
- yes I agree
1) a somewhat vague subjective goal or intention which is held in conscious awareness;
- well it may not be at all vague, but it is subjective in the sense that it is in the mind of a conscious agent
2) an ostensibly-objective evaluation of the place/ usefulness/ necessity of organisms/ organs/ molecules in an ecosystem or part-ecosystem;
- yes: eyes have the function/purpose of enabling vision, hemoglobin has the function/purpose of transporting oxygen in the blood stream, wings enable flight, and so on;
3) a hypothetically-existing higher-level external-to-the-universe master-plan that somehow guides outcomes in the universe, in addition to laws-of-nature. I think that there is no evidence of 3).
- I have not entered that discussion at all here. It plays no role in my essay.
> Re "Purpose in the sense of function is necessary for all physiological systems": I wouldn't say that purpose (in the above 3 senses) is the same as function. The then meaning of the word "function" ("power of acting in a specific proper way") was appropriated by Leibniz in 1673 to refer to mathematical functions, seemingly because the function ("power of acting in a specific proper way") of a mathematical model is completely determined by its mathematical function.
- well mathematical functions only operate in abstract spaces, unless human minds use them for say engineering purposes, when they do indeed cause change in the real world (see Seventeen Equations that Changed the World).
- This is however different from what Hartwell et al talk about
> Nothing has changed: despite the visual appearance of some complex system models, no new function evolves out of a deterministic modelled system because the mathematical function completely defines the function ("power of acting in a specific proper way") of the modelled system.
- agreed
> By analogy with models, for new function to emerge in the universe, the equivalent of new mathematical functions/rules have to be added to the complex universe-system.
- It is key to separate ontology from epistemology here. As a mathematical Platonist, I believe that maths per se is timeless and unchanging. However what we know about maths is culture dependent and changes with time. No new functions or rules can be added to the Platonic reality; they are what they are. We can however learn more about them and use more of them in engineering applications through the operations of our minds. In that sense new functions/rules have to be added to the system.
> Human beings can add new rules to a model system, but the actual universe is not a model.
- yes
> Seemingly by definition, there is nothing external to the universe. That is why I contend that the universe must generate its own rules.
- As the universe is not conscious, I don't know what that means. Whatever happens in the universe is governed by a set of unchanging eternal rules ("Laws of Nature", as described by the standard model of particle physics together with general relativity). The universe has no option but to obey them (whatever that means).
