Fundamental premise of the skeptics that it is impossible for humans to have objective knowledge of reality or anything else

Is it Possibly True?

It's difficult to definitively disprove the skeptical argument. We can point to scientific advancements that seem to reveal objective truths about the universe, but the skeptic can always counter that our scientific instruments are themselves subject to interpretation and could be fundamentally flawed in ways we don't yet understand. Even seemingly basic perceptions – like the color of an object – can be shown to vary slightly between individuals due to differences in their eyes. So, the possibility that we are trapped in our own subjective experience remains a persistent challenge.  

What Does Science/Philosophy Say?

• Science: Science, while striving for objectivity, acknowledges the limitations of human perception. The scientific method emphasizes empirical observation, testing, and peer review precisely to minimize the influence of subjective biases. However, science also recognizes that its models of reality are just that – models – and are subject to revision as new evidence emerges. Quantum mechanics, in particular, has raised questions about the very nature of reality and the role of the observer, further complicating the issue of objective knowledge.  
• Philosophy: Philosophical debates on skepticism have raged for centuries. Some philosophers, like Descartes, attempted to find a foundation for certain knowledge through reason (e.g., "I think, therefore I am"). Others, like Hume, argued that our knowledge is ultimately based on habit and custom, not on any direct access to reality. More recent philosophers have explored different ways of addressing skepticism, such as focusing on the practical usefulness of our knowledge claims, even if they are not absolutely certain, or emphasizing the social and intersubjective nature of knowledge.

Is the Argument Self-Defeating?

The skeptical argument, when pushed to its extreme, can be argued to be self-defeating. The claim that "we cannot have objective knowledge" is itself a claim to knowledge. If we truly couldn't have any objective knowledge, then we couldn't even know that we couldn't have objective knowledge. This paradox doesn't necessarily invalidate all skeptical arguments, but it does suggest that some forms of radical skepticism are logically problematic.

Conclusion:

The question of whether we can have objective knowledge is a complex one that doesn't have easy answers. While the skeptical argument raises valid concerns about the limitations of human perception and the possibility of bias, it doesn't necessarily follow that all knowledge claims are equally suspect. Science and philosophy continue to grapple with these issues, and the debate is likely to continue. In practical terms, we must acknowledge the possibility of error and bias in our knowledge while still striving for the most accurate and reliable understanding of the world as possible. We can do this by embracing the scientific method, engaging in critical thinking, and being open to revising our beliefs in the face of new evidence.