9 Comments
Jun 8Liked by Michael Huemer

This will give me something to ponder about for a good while. Thanks.

Expand full comment

The problem I have in accepting the concept of synthetic, a priori knowledge is in explaining where it comes from. I can understand that it might be in our genes to acquire such knowledge in early childhood, but our genes are presumably the way they are because that kind of knowledge contributed to the survival of our ancestors.

Expand full comment
author

It comes from grasping abstract objects. E.g., understanding what green is and what red is leads to the knowledge that nothing is completely red and completely green. Understanding what 'lines' are and what 'distance' is leads to the understanding that the shortest path between a pair of points will be a straight line. Etc.

Expand full comment

Thanks. I just checked whether there is evidence that people who are born blind can understand the concept of colour. Apparently they can reason about colour without ever having seen it.

Expand full comment
author

They may be reasoning based on what other people told them.

Expand full comment

I expect that is correct. So, could it be argued that they acquire the concept of colour via their hearing senses?

Expand full comment

I thought all Bayesian accepted that prior probabilities were not determined by Bayes' rule. If thinking you can have any prior is subjectivist Bayesianism, what are the alternatives (presumably objectivist Bayianism)?

Expand full comment
author

Right. "Objective Bayesians" introduce principles that go beyond the Kolmogorov axioms, to constrain prior probabilities. The most popular such principle is probably the Principle of Indifference, whereby if there is no reason to favor a possibility A1 over A2 or vice versa, then the initial P(A1) = P(A2).

As I explain elsewhere, this approach can be used to solve the problem of induction. (https://fakenous.substack.com/p/explanationist-aid-for-the-theory)

Expand full comment

The trick seems to be defining what is “rational” for priori probabilities.

Expand full comment