I just know it.

We’ve all heard it before.  Whether it’s someone of the religious persuasion attempting to convince you of their deity of choice or your best friend assuring you that he’s going the right way to the party, this phrase has cropped up more than enough times in conversations across the world to last each of us a lifetime.

A couple of months ago, I was cornered by a friend who brought up this very issue with me. They posited that it was possible to simply know something to be true without having any evidence. Certainly this claim seems ridiculous. Of course, I cannot refute the thing that they ‘know’ without evidence, which can make refuting certain ideas difficult. An idea without any evidence to support it is simply that: an unsubstantiated idea. You may believe it all you like, but good luck convincing anyone that you’re right.

This topic has actually come up a lot over the past few months. My friend earlier this week and I were talking about knowing things – how can we authoritatively state that we actually know something to be true? Well, the short answer is that we can’t. Because of the limited understanding that we as humans have, we cannot truly claim to know anything; pure, unadulterated knowledge is beyond our grasp, and we must make due with our limited data and make the best conclusions we can. We can’t claim that there is no god, just as we can’t claim that there is. (If you do find anyone making such gnostic claims, I would love to hear their reasoning. Maybe they’re seeing something the rest of us aren’t.)

Take gravity, for example. Gravity is just a theory. A scientific theory, mind you. That means that there is an enormous amount of evidence supporting the claim that what we call gravity exists. We can observe its effects on us and how it effects us daily, and we can see how it effects our universe. Ergo, the theory of gravity. Now, within this umbrella term ‘theory’, there exists a word we refer to as ‘laws’. With the case of gravity, we have things like Newton’s Universal Theory of Gravitation and Einstein’s General Relativity. Newton’s theory provides an excellent explanation of how gravity operates within our universe (how it is the direct relationship between two masses inversely related to the square of the distance separating them), whilst Einstein’s theory helps us to understand gravity in more extreme circumstances. Now, these laws are by no means a sort of ‘end-all’ to what gravity is: they are merely human interpretations and definitions of gravity. Gravity clearly exists, although maybe not entirely as what we claim it to be.