Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and make… - Stephen Hawking

Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and
makes a universe for them to describe?

As I shall describe, the prospects for finding such a theory seem to be much better now because we know so much more about the universe. But we must beware of overconfidence - we have had false dawns before! At the beginning of this century, for example, it was thought that everything could be explained in terms of the properties of continuous matter, such as elasticity and heat conduction. The discovery of atomic structure and the uncertainty principle put an emphatic end to that. Then again, in 1928, physicist and Nobel Prize winner Max Born told a group of visitors to Gottingen University, "Physics, as we know it, will be over in six months." His confidence was based on the recent discovery by Dirac of the equation that governed the electron. It was thought that a similar equation would govern the proton, which was the only other particle known at the time, and that would be the end of theoretical physics. However, the discovery of the neutron and of nuclear forces knocked that one on the head too. Having said this, I still believe there are grounds for cautious optimism that we may now be near the end of the search for the ultimate laws of nature.

The universe doesn't allow perfection.

The most remarkable property of the universe is that it has spawned creatures able to ask questions.