The Three Branches of Evidentialism

If we work with the definitions of truth and knowledge as laid out in previous posts, then we begin to see an epistemology form that looks a lot like evidentialism. Evidence can be strong or weak with respect to a conclusion just like we can have varying degrees of certainty with respect to our knowledge. A perfect fit.

In philosophy, it generally goes uncontested that beliefs should be supported by evidence. It doesn't really make sense to have it any other way. But isn't there a problem here? Don't our beliefs about evidence have to be supported by evidence also? We could be stuck here forever wondering about how to justify the evidence for the evidence for the evidence for the evidence of something. No matter what we do, true justification is out of reach... or is it?

Philosophers have thought about this "infinite chain of evidence" problem. However, there are varying positions available on how to solve it.

Philosophical Skepticism

In this view, no belief is truly justified. This position essentially gives up on trying to justify any belief at all because it claims the problem is unsolvable. This position is useless to me. If justification is impossible, what's the point of even thinking about all this stuff? I need a system that helps me form beliefs as accurately as possible... not one that prevents me from forming any at all... or worse, makes belief arbitrary.

Coherentism

In this view, the beliefs at the end of the chain are justified if they all harmonize and make sense together. While this does solve our "infinite chain" problem, it creates another. This easily allows for beliefs that have no basis in reality. I can come up with a complex set of coherent beliefs about the intricacies of what happens to me after I die... but that doesn't mean those beliefs are true. If we don't have assurances that those beliefs are true, they cannot be justified. Having assurance of truth is, after all, what justification is all about.

Foundational Evidentialism

In this view, the beliefs at the end of the chain are justified when they are "self-evident." In the most common form of Foundational Evidentialism (aka Foundationalism), self-evident beliefs are formed directly from our senses. When we hear a bird or see a sun-rise, these things are self-evident.

This system ensures that our beliefs will be based in reality because sensory perception is the foundation for all other derivative beliefs. This also solves the "infinite chain" problem by ending each chain in something seen, heard, touched, smelled, tasted, etc.

Our method of justification, then, is to start with the truth claim and work logically backward toward the self-evident observations that justify it. It also gives us a means of discovering (unclaimed) truth, which is the same method in reverse: Start with self-evident observations and work logically forward toward the truth. This is the foundation of the scientific method and science has proved its usefulness time and time again.

In the next post, we'll examine a few examples and see how Foundational Evidentialism is used in practical, everyday situations.