In his seminal Tractatus Logico-Philosophicus, Ludwig Wittgenstein sets forth a striking philosophy that begins with this very word "facts", or "Tatsachen" in the original German text.
1. The world is all that is the case.
1.1 The world is the totality of facts, not of things.
1.11 The world is determined by the facts, and by their being all the facts.
1.12 For the totality of facts determines what is the case, and also whatever is not the case.
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1.2 The world divides into facts.
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2. What is the case, a fact, is the existence of states of affairs.
2.01 An atomic fact is a combination of objects (entities, things).
According to Wittgenstein, an 'atomic fact' ('Sachverhalt') is a combination of objects ('Gegenständen' or, literally, 'things-standing-against'). A fact is merely a combination of these atomic simples, these irreducible entities or things which form the logical material and composition of the world. An actual combination of Gegenständen is a fact. Gegenständen are all that can be, and so, the world is only the totality of combination of these simple objects. Hence: 'The world is a totality of facts, not of things'.