Werner Heisenberg writes of the nature of reality and of the fundamental basis of matter in Physics and Philosophy, as he recounts the ancient philosophy of the Greeks;

The process of Becoming is considered a sort of debasement of the infinite Being – a disintegration into the struggle ultimately expiated by a return into that which is without shape or character. The struggle which is meant here is the opposition between hot and cold, fire and water, wet and dry, etc. The temporary victory of one over the other is the injustice for which they finally make reparation in the ordering of time. According to Anaximander, there is ‘eternal motion', the creation and passing away of worlds from infinity to infinity.

He goes on to suggest that the problem of physics is one of identification of the primary substance. But rather than taking a scientific perspective in relation to the problem, let's take an existential one.

Of what are we made, and what is our place in the constant flux we call reality?

As I sit around the dinner table with my wife and children, there comes upon me the unnerving realisation that how I perceive myself is not how I am perceived.

There is nothing new here, other than this time, the realisation has a particular gravity that I haven't felt before.

My children are quite literally shaped and moulded by me. Not entirely, other factors come into play, such as everyone else around the table and the broader environment.

But there is something in all of this that makes me realise, like never before, that this thing I refer to as me doesn't really exist.

Take a longer timeline, and the chair, the wall, the mountain, and so on, don't really exist either. Yet they all exist at any given moment.

I believe that there are few greater exercises of thought than to consider oneself non-existent. And rather than getting down on all of that, we can smile at the futility of all our struggles.

We can perhaps accept that we're not such a big deal.

Werner Heisenberg, Physics and Philosophy