We can't have truth, perhaps our descendants one day will. But we can have clarity. Clarity regarding theoretical knowledge involves at least three things. The degree of certainty (never absolute, but more or less speculative), the degree of application and the degree of articulation regarding other theories.
If we live in a sea of uncertainties where even cartesian certainty can't help us regarding fundamental truths, then we have no solid basis, no rock, on which to build the foundation for the rest of knowledge. The senses can be misleading (like if we live in a simulation), logic and mathematics may be only on our heads, limiting or distorting the true vision of reality (a result of a simulation or simply of billions of years of evolution that has shaped our minds to the particular conditions homo sapiens must live in), the "if I think therefore I exist" leads nowhere and is itself terribly vague, and, of course, Descartes' attempt to base everything on the existence of a benevolent God was as social undoubtful at the time as it is laughable today (even in most religious circles where God is taken as something that cannot be proved but must be believed).
Another view that has been proposed more recently (as far as I know) was that of coherentism or the holistic view of knowledge, proposed by Quine ...
As a species who is just waking up to the universe we live in a sea of uncertainties where even cartesian certainty can't help us regarding fundamental truths. We have no solid basis, no rock, on which to build the foundation for the rest of knowledge. The senses can be misleading (like if we live in a simulation), logic and mathematics may be only on our heads, limiting or distorting the true vision of reality (a result of a simulation or simply of billions of years of evolution that has shaped our minds to the particular conditions homo sapiens must live in - perhaps quantum logic is closer to reality).
So the pieces and bits that we were able to gather form like small walking areas in this vast ocean of ignorance. Some of these areas are like floating rafts, small and insecure, while others seem so unshakable that we can't really tell if they are like rock-solid islands or melting icebergs. Unfortunately we don't yet see the bottom of the Ocean, the root of reality, to check if our theories are just passing fancies or truths in context, or if they really grasp something that is really real (a reality that could never cease to be). Here the analogy ceases to work for in the case of the Ocean we can imagine what it is like to find a rock foundation that goes to the core of the planet. But we cannot imagine what "real reality" would be like, or how we would be able to access it. For even the most obvious things to us may be an illusion. The fact that our whole world may be just a simulation shows well that we cannot really know for sure that our bodies exist, that other people are conscious or that the infinite universe around us exists outside us. What could give us such certainty? What kind of discovery could prove that the world is not a mere simulation? Can you imagine one? I don't think anyone was ever able to come up with a possible experiment to prove that. Is there another way, perhaps something that does not involve
, sometimes so distant from each other that it is difficult to pass from one to the other. The most clear example of such floating rafts are mathematics and religion. Both deal with inner experiences. Mathematics comes from what cannot be imagined in some