Most generally, a brute fact is roughly something that is self-evidently true and without explanation, and claims about the necessity and contingency of claims is a byproduct of different and UNNECESSARY metaphysical first principles. In the prior post, the attempt to link what might be seen as an epistemological characterization of brute facts regarding their necessity and contingency is itself not a metaphysical necessity. Modal logic and possible-world text is itself unnecessary in making and defending claims (though obviously impoverished from a conceptual view, modality and probability being a wonderful addition to logic.)
What is a brute fact if one discards the logical and epistemological tools of necessity and contingency? A brute fact.
The (Unnecessary) Connection between Brute Facts and Modal Logic
Both brute facts and modal logics are both obviously epistemological topics since they deal with knowledge, which for the sake of this conversation, we'll just characterize as the product of JTB+, justified, true belief with one or more additional criteria to deal with Gettier's largely, unpragmatic objection. Let's make some observations:
Human reason is largely informal and very defeasible. Humans are not deductive-logic machines that execute formal systems. Certainly, Euclid's Elements was a transformational product in knowledge. Deductive reasoning was held up as a model for good logic for thousands of years in a mania that borders are on religion. It's good stuff. But David Hume among others poked a hole in widespread claims that the only reason is deductive reason, even though the scandal of induction taught an important lesson. Abduction also is an important type of logical methodology. The fact that formal systems didn't really even catch on until after Gottlob Frege set analytic philosophical circles on their path shows how unnatural deductive systems are (a fact that's apparent if you ever teach a geometry class to teenagers).
Modal logic is one method of logic, but it is not strictly necessary in logical discourse, as useful as it is in inductive reasoning. As someone with strong empirical beliefs, I find modal realism utterly indefensible since it fails to meet even the basic requirements to overcome Russell's teapot. Every thinker must balance two unbalanced positions, that of radical skepticism that knowledge fundamentally doesn't exist, and that of faith, that one can have knowledge without rational or empirical proof. A brute fact is roughly a pragmatic line in the sand in this goal of balance, and one doesn't have to even examine whether or not they are necessary or contigent because they carry perceptual and intuitional force. The existence of brute facts is contingently a brute fact itself, and one of the goals of philosophy is to explain them.
Modern psychology recognizes how there are cognitive and emotional biases in reason, and for good cause. There are cognitive and emotional biases in reason. Reason is often abused by thinkers, starting and not ending with formal fallacies. Anyone who has ever raised a child knows that humans from birth are constructed to want first, and rationalize second. Most 5-year olds are pretty good at explaining why their beliefs justify their desires.
So, it is important to use modal logic, no doubt about it. But it is not necessary to make claims. It does help constrain reality and helps humans make sense of the world, and clearly separates us from our Great Ape cousins Pan troglodytes, Pan paniscus, and Gorilla gorilla. We make language and it enriches our mental lives particularly through the material inference, the hypothetical, and the counterfactual conditional. These activities are so important, they are built into our vocabularies and grammars, such as the subjunctive case among PIE speakers
- Past brute facts can often be explained with an advance in knowledge and technology (hence the sciences), but there is simply NO good argument to say that ALL physical brute facts are contingent and will or can be explained. In fact, fallibilism which acknowledges both the defeasibility of human reason and the practical limits of logic including scientific underdetermination and various incompleteness theorems, not to mention Gettier dashing any hopes at a simple characterization of knowledge, calls for a defense of that claim. Fallibilism essentially underlines that knowledge is constantly in flux, is constantly being rebuilt, and that it is imperfect, which like in war where such imperfect knowledge is called the fog of war a la Clausewitz.
The Nature and Purpose of a Brute Fact
Simply put, a brute fact is the pragmatic acceptance to practice moderate foundationalism. From WP:
As an alternative to the classic view, modest foundationalism does not require that basic perceptual beliefs are infallible, but holds that it is reasonable to assume that perceptual beliefs are justified unless evidence to the contrary exists.25 This is still foundationalism because it maintains that all non-basic beliefs must be ultimately justified by basic beliefs, but it does not require that basic beliefs are infallible and allows inductive reasoning as an acceptable form of inference.
A brute fact simply is a self-evident; an unproved, but generally intuitional or even perceptual claim that serves the purpose of allowing for more sophisticated reason. And in the course of that defeasible reasoning, if it comes to light the brute fact is actually wrong, so be it. Or perhaps the can gets kicked down the road and today's brute fact becomes tomorrow's fact based on theory, so be it. Another brute fact will be claimed to continue the process of important reasoning. And there simply is no need to engage in grand metaphysical speculation about the nature of brute facts any more then there is to understand material science to drive a car.
@JD Could you please give an example of a brute fact being something that is "self-evidently true and without explanation". I assume a brute fact is not just a correct analytical statement. – Jo Wehler
@JoWehler Sure. "A container is larger than its contents." Is this not self-evident? Have you ever seen a container contain something larger than itself? Can you explain why this is true without begging the question? What is it about extensionality that makes this true without exception? It is a self-evident and a brute fact. – JD
The fact that the content is less than the container follows from two statements which are analytically true: 1. The content is a subset of the container. 2. Volume can be compared by filling with small standard cubes. IMO the explanation of the original fact reduces to the set-definition and to the volume-definition. - Jo Wehler
Absolutely. No doubt. We are in agreement there. But, the property of the extension of space such that mastodons fit in caves only bigger than them precedes both the set-definition and the volume definition, or any other definition you can cook up in any language simply because the property in question inheres to time-space which existed long before there were eggs heads to cook up definitions. The difference is vaguely addressed here in "self-evidence" (WP). As suits physicalism, language is a tool that reflects the physical state of affairs, and while one can demonstrate contradictions of language, some contradictions are linguistic artifacts that reflect the necessity and contingency of the physical world independent of language. It is an empirically true statement that it simply is not possible to stuff 10lbs of poop in a 5lb bag, which is a necessarily true fact independent of linguistic convention.
I would say attempts to claim that physical reality is constrained by language, generally, reflects the fallacy of mistaking the map for the territory. The analyticity of a claim is charge d'affaires of truth when it comes to physical descriptions. While it is readily possible to show the contradiction inherent in the symbols, and that is a useful tool doubtless, the truth of the proposition lies in it's correspondence to reality. So, here we see coherence in the rational and correspondence in the empirical simultaneously.
Thus, "A container is larger than its contents" is true ULTIMATELY because a container is larger than its contents. This is epistemologically speaking the quintessence of disquotationalism. You may of course, challenge that strictly speaking my use of the analyticity when I invoke disquotationalism, since I am blurring the lines between the analytical and the synthetic, and you would be encouraged to do so, because it would lead you to Quine's objection to the distinction Two Dogmas which I believe raises the obvious objection that you attempt to create two mutually exclusive classes of claims is artifice that cannot ultimately be sustained despite it's general utility.
In short, where you and I seem to differ is that you seek to make the brutishness of the truth merely in language, where I elevate your claim to a metalanguage so that the brutishness lies in the object language. You can reject my subsumption of your claim to an abstraction correlated to a physical experience, but I'd of course would wonder why.