My advanced apologies if my question is not appropriate for this website. This is my first semester of Philosophy so I hope I'm not asking obvious, low-level questions.
I have been reading Plantinga's argument against naturalistic evolution and have come across the following understanding:
According to Plantinga, believing in naturalism and evolutionary theory is self-defeating; if one believes in the naturalistic evolution of beings, then he/she believes that the main purpose for our cognitive faculties has been to evolve to enhance survival and reproduction, without much consideration for producing true beliefs. The latter part allows us to logically deduce that all beliefs held by naturalists are, according to their own view, not reliable. Thus, their very belief in naturalism is undermined. Hence, the self-defeating idea of naturalistic evolution of beings.
Hoping my understanding is correct, I have the following questions I'm seeking clarifications on:
- In my class, we talked about the idea of an undefeatable defeator. Is this the same as self-defeating?
- The naturalistic evolutionary theory believes in a blind and unguided natural processes. How is it different from the evolutionary theory (standard one)?
- When Plantiga presents possible cases for Darwin's doubt (fact that the conditional probability of cognitive reliability
P(R|N&E)is low), he uses as one of the possibilities the case where beliefs are maladaptive. He claims that because of this,
P(R|N&E)is too low. But, if beliefs are maladaptive, isn't it rational to argue that most of them would have disappeared through evolutionary processes, and thus what remains makes for a larger share of reliable cognitive faculties, thus a higher
- What does
P(N&E)mean in terms of philosophical words? Is it simply the probability that a person picked at random believes in naturalistic evolution theory?
- [Most important question] Could someone please explain Plantinga's argument when he presents Bayes's theorem and proceeds with some math? I understand conditional probabilities, so it's not the math I don't get, but rather his assumptions and development through the argument. For example, he says to give
P(R)a high probability of 1, which means we highly believe that our cognitive faculties produce reliable beliefs. But then, he says to give
P(R|N&E)no more than 1/2. This would be true for someone who does not believe in our cognitive reliability, whereas we just assigned
P(R)~1. I'm greatly confused on this part of the development.
Update on Question 5
After consulting with my professor, it seems like I understood the probabilities incorrectly.
P(R) is the standalone probability that our cognitive faculties are reliable. Based on our intuition and everyday life, it would be reasonable for us to believe we are correct in most of our beliefs, so we can assign
P(R)~1. On the other hand,
P(R|N&E) indicates the conditional probability of R being true given N&E only. By definition of conditional probabilities, one cannot allow any other information other than N&E determine the probability of R. That is, compared to the former case, we cannot rely on our intuition and everyday experience to assign a value to
P(R|N&E) but rather we must solely rely on the conditionals, N&E, to determine
P(R|N&E). Combining this with Plantiga's argument that naturalistic evolution picks for survival and reproduction traits and doesn't concern itself with the formation of true beliefs, I can see why he would give
P(R|N&E) a value less than 1/2.
I think this explanation makes sense. Although I'm certain it is open to discussion if this interpretation is true. I would love some input.