In contemporary philosophy, a brute fact is something that cannot be explained. To reject the existence of brute facts is to think that everything can be explained. ("Everything can be explained" is sometimes called the principle of sufficient reason). There are two ways to explain something: say what brought it about, or describe it at a more "fundamental" level. For example, the fact that there's a cat on my computer screen can be explained, more "fundamentally", as the fact that there are certain voltages in bits of metal in my screen, which in turn can be explained, more "fundamentally", as the fact that there are certain subatomic particles moving in a certain way. If we keep explaining the world in this way and reach a point at which no more "deeper" explanations can be given, then we have found some facts which are brute or inexplicable, in the sense that we cannot give them an ontological explanation. As we might put it, we have some things that just are. We can do the same thing with causal explanations. If nothing made the big bang explode at the velocity it did, then this is a brute fact, in the sense that it lacks a causal explanation.
Brute/scientific fact 
G. E. M. Anscombe employed the concept of a fact being a brute fact relative to some other fact - the brute fact of paying a bill by handing over some money presupposing for example the existence of an institutionalised currency system. Thus some facts seem to be dependent on others: that a certain piece of paper is worth ten dollars can be explained in terms of the human choices, beliefs, and institutions that support the currency system.
John Searle developed Anscombe's concept of brute facts into what he called brute physical facts - such as that there is snow on Mt Everest - as opposed to social or institutional facts, dependent for their existence on human agreement. Thus he considered money to be an institutional fact, which nevertheless rested ultimately on a brute physical fact, whether a piece of paper or only an electronic record.
Searle thought that the pervasiveness of social facts could disguise their social construction and ultimate reliance upon the brute fact: thus we are for example trained from infancy (in his words) to see "cellulose fibres with green and gray stains, or enamel-covered iron concavities containing water...[as] dollar bills, and full bathtubs".
The principle of sufficient reason is sometimes understood to entail that there are no brute facts.
See also 
- is and ought problem – the distinction between factual claims and value or normative claims
- matter of fact and matter of law
- First principle
- John Hospers, An Introduction to Philosophical Analysis (1997) p. 211
- Gary Gutting, French Philosophy in the Twentieth Century (2001) p. 32
- Gutting, p. 34
- John R. Searle, The Construction of Social Reality (1995) p. 34=5
- Searle, p. 121 and p. 1-2
- Searle, p. 56 and p. 4
Further reading 
- "Brute Fact". Oxford Companion to Philosophy. 2005.
- Anscombe, G. E. M. (1958). "On Brute facts". Analysis 18 (3): 69–72. JSTOR 3326788.
- Nicholas, Bunnin; Yu, Jiyuan (eds.). "Brute fact". The Blackwell Dictionary of Western Philosophy.
- Rosen, Gideon (2010). "Metaphysical Dependence: Grounding and Reduction". In Hale, Bob; Hoffmann, Aviv. Modality. New York: Oxford University Press. ISBN 9780199565818.
- Melamed, Yitzhak; Lin, Martin (2011). "Principle of Sufficient Reason". In Zalta, Edward N. The Stanford Encyclopedia of Philosophy (Fall 2011 ed.).