How can you tell if you know something? There are two diametrically opposite theories of knowledge to answer that question.
The first theory relies on confidence. It entails making repeated observations and becoming surer of our observations with time. If the sun rose in the east yesterday, the day before, and for all recorded history, we can be more confident that it will rise tomorrow in the east. With each observation that confirms our assumption, we grow more confident in our assumption.
This theory of knowledge is called the ‘justified true belief’ theory. We are naturally prone to reasoning this way – we are conditioned to do so. Even animals reason this way. When a bird recognizes that it is safe to perch on a particular branch, it is likely to keep returning to that branch.
The second theory relies on humility. It is based on a simple but baffling premise – that we are incapable of knowing anything at all perfectly. Every bit of knowledge we have is merely our best guess at something we can never know for sure. Newton’s gravitational theory was our best guess until general relativity came along. Now general relativity’s warping of space-time is our best guess until a better explanation comes along.
This second theory of knowledge is called epistemology. It believes that our best theories of today in every field are merely a framework for tomorrow’s scientists to improve upon, while pursuing a construction project that will never be finished.
The advantage of the justified true belief approach is that it is intuitive. Its problem is that we are most confident about a theory precisely the moment before it is demolished. For the longest time, the western world believed that the Sun revolved around the Earth. The moment Nicholas Copernicus proved otherwise, they were so confident of their assertion, that they refused to believe him and even threatened to kill him.
The disadvantage of epistemology is that it is counter-intuitive. It can also be depressing to know that we would never truly know anything at all. Yet, epistemology calls upon creativity, imagination and our powers of reasoning to propose ever more elegant explanations of the nature of reality.
Realizing that we are incapable of perfectly knowing anything at all replaces hubris with plenty of room for discovery and exploration.