Epistemology is the branch of philosophy that deals with questions about what constitutes knowledge, rationality, justified belief, etc. Your opinions about how we know things, the limits of what we can know, and what constitutes a good standard for evidence are the elements that comprise your epistemology. Everyone has an epistemology whether they consciously reflect on it or not. When people say things like “there is no truth” or “the truth is absolute,” they’re expressing a very specific epistemology. When people say things like “truth can’t be known” or “beliefs are only rational if they’re backed by science” or “science isn’t the only way to know truth,” they’re expressing their epistemology.
It is literally impossible to not have an epistemology. Whenever people argue or make claims about the world, their claims are based on very specific understandings about the nature of truth and knowledge. This is an inescapable aspect of all forms of reasoning. Different people can have different views about what constitutes good evidence. Different people can have different views about what truth is and what it means to know something. A religious person who accepts what the bible says, for example, has different epistemic presuppositions than an atheist who rejects the concept of divinely inspired books. These differences are rooted in their respective epistemologies. That’s largely the basis of their disagreement and debate.
To say that someone is making philosophical presuppositions isn’t an insult or a criticism. It’s just a simple fact that logically follows from the very nature of reasoning and communicating. Philosophy underlies everything we do. That’s not inherently bad. It just is what it is. To say things like “we don’t need philosophy” betrays a misunderstanding of what philosophy actually is. You may not need to declare a major in philosophy at a university. You may not need to read Plato and Aristotle. That’s all fine. But it’s impossible to not do philosophy. We all have fundamental ideas about the nature of reality, the nature of knowledge, the nature of morality, and the meaning of life. Philosophy is nothing less than the investigation, analysis, or application of these fundamental ideas.
Philosophy is inherent in all we say and do. You may not do it consciously, but you’re doing it. You may not like using the word “philosophy,” but a rose by any other name is a rose still the same. Even when you say “philosophy is irrelevant,” you’re making a philosophical statement about what matters in life. We can do philosophy badly or we can do it well. We can do philosophy consciously or we can do it unconsciously. It’s up to us. The important thing to remember is that we have a choice.
We can’t avoid philosophizing, but we can choose to think consciously, critically, and creatively when we do it. When we do philosophy that way, we tend to get more out of it. And when we get more out of our philosophy, we usually get more out of life.