How does Darwin's Theory of Evolution complicate a reading of Kant's Groundwork for the Metaphysic of Morals?

Question

Darwins Theory of Evolution states that the evolution of life underlies processes like selection, reproduction and variation. I think, essentially he says, that the occurences of any ability or property are completely random and the survival of some of them depend on the natural environment and nothing else. I guess this also includes the development of mind or human reason. So human reason may as well not exist at all.

But in his Groundwork for the Metaphysic of Morals Kant says:

We take it as an axiom that in the natural constitution of an organized being (i.e. one suitably adapted to life) no organ will be found that isn’t perfectly adapted to its purpose.

And later:

So reason isn’t competent to act as a guide that will lead the will reliably to its objectives and will satisfy all our needs (indeed it adds to our needs!); an implanted instinct would do this job much more reliably. Nevertheless, reason is given to us as a practical faculty, that is, one that is meant to have an influence on the will. Its proper function must be to produce a will that is good in itself and not good as a means.

His argumentation completely relies on an axiom that is incompatible with the Theory of Evolution.

I always understood Kant's ethics to build on nothing but reason, because of his argumentation above.

So to what extent does Darwin's theory argue against Kant's moral philosophy?

Answer 1

Does that mean that if Darwin's theory is right, Kant's whole moral philosophy becomes worthless, because his axiom does not hold?

No, it means that Kant's whole moral philosophy is imperfect. That's not a big shock; I don't think anybody (outside of Kant himself) actually thought that it was.

I think that there are very few today who would doubt that humans are not perfectly rational, and that any attempt to ground an ethics in pure rationality is going to be incomplete at best. But that does not mean that Kant, or his moral writings, are worthless; on the contrary, they remain important works to grapple with in any later ethical developments.

Answer 2

Interestingly I don't think Kant & Darwin are incompatible. In fact, I am begining to think they are actually two components of a much larger model on the development of 'success.' Darwin's idea that attributes are random is not really relevant to Kant's point. I would submit there is a slight missreasing. Darwin posits that features are random in their development or that nature does not develop features purposefully. But in a sense nature does. Features develop in a particular environment and support the continuation of both a feature and creature. Evolution selects the features which lead to reproductive success. Evoltion is the process of nature. Therefore nature is not random it is experimental. And like in the concept of brainstorming it doesn't matter where 'ideas' about a problem come from, each is put on the table and reviewed. In a sense Darwin was stating features, like ideas, appear and there source is not important in the evaluation process. The feature's reproductive success is critical.

And this leads to Kant. All 'organs' fill a specific purpose. Meaning the existence of the 'organ' implies, by its existence, that it has supported reproductive success and therefore is fullfilling some purpose.

Of course this ideas maybe filled with extaneous blather that will be filtered out as it's reproductive success is refined.