In reference to my post about models that account for the same data, one possible explanation for why there are so many religions is because of the principal component function in our minds (refer to the post). Here, we have the same data. But we refer to different dimensions to explain the data. Sometimes even omitting certain dimensions. Such omissions would lead to certain biases in explaining the data. And to the extent that the bias is critical (that is, to the extent that these biases are necessary for accounting for the truth), our explanation of the data will be off from reality. To the extent that the biases are not critical, we will not be off from reality.
The most accurate model therefore, is the one that most closely matches reality. Yet how are we to know reality? This is the problem of knowledge. Can we truly ever know anything since we are limited to our senses, five in all, and perhaps a little more. We have 5 dimensional information, and perhaps a little more. What if the data were more multi-dimensioned than our senses can experience? Even if we had secondary ways of measuring data from dimensions beyond our perception, our experience is still bounded by our perceptions. Thus, it appears that to ascertain reality, we need to transcend our 5 senses. But even then, how many senses or dimensions should we transcend? In theory, infinite. Which is of course, flatly impossible.
Therefore, the question is not about empirical proof anymore. We realize empiricism, limited to 5 senses, cannot ascertain reality. Really, all empiricism does is to come up with models to account for data within the 5 senses. Which has no consequence on reality itself.
We are back to the question: How can we know what reality is?