Consider the following hypothesis:
Everything has an explanation.
If this is false, all efforts to search for the ultimate truth, by scientists and sages alike, are futile.
The ability to explain everything implies that the universe follows well-defined ubiquitous laws that govern everything. Existence of such a universal law (or laws) allows us to link any event in the universe to at least one other thing. Similar to how cause and effect are linked. However, such linking need not be limited to temporal or spatial concepts. It needs to be just a link, doesn’t matter what kind. An explanation, by definition, is but a way of linking one thing to another. In other words, it’s a mathematical function of at least two variables. So if everything has an explanation, then everything is linked to at least one other thing in the universe, implying the basic nature of the universe as being dualistic. Nothing can be standalone. At the minimum, there are two distinct fundamental building blocks to this universe.
The existence of all-encompassing laws governing everything in the universe implies that the brain and its associated mental apparatus used to understand these laws is also functioning under these same inviolate laws. That further means that the thought pathways that don't follow these laws can never be created in the brain. These rules will constrain us from being completely free and comprehensive in our thinking. There will always be a finite chance that there exist natural phenomena that our brain is incapable of processing fully.
Another underlying assumption in the hypothesis is that there must exist a knower capable of understanding all of those explanations. If ultimate truth exists then the universal laws that govern it must allow for an entity that can comprehend it. Explanation is a concept that is tightly coupled with complementary concepts of an intelligent entity. An explanation is always for someone. An 'explanation' should be able to make somebody understand something. If it can't make anybody understand anything, then it simply means that it is not an explanation. In order for an explanation to exist, there must be an entity that 'can' understand (or process) it.
If explainability exists, then everything can be explained, including the behaviour, actions and thought processes of the one who is trying to understand it. But it directly implies what follows next:
There can be no God, if explainability exists.
The ultimate intellect that can process the ultimate truth must lie outside the bounds of the laws that make explainability possible. This is necessary as this mental machinery should not be constrained so that it can freely explore all possible pathways. Such an intellectual being might very well exist. However, such a proposition threatens the fundamental framework on which we base all our intellectual activity. If an entity exists that doesn't follow any laws, then by our earlier arguments, this entity cannot be explainable. This creates a contradiction with our initial assumption that everything is explainable.
On the other hand, if an ultimate intellect doesn't exist, then there's nothing that can understand the Ultimate Truth. So, the Ultimate Truth just doesn't exist. It's not just about knowing or not knowing, but about the very existence of this so-called Ultimate Explanation.
It's possible that the above paradox is a result of inadequate reasoning methods. It's also possible that the procedure of analysis here is flawed somewhere. Or perhaps the logic needed for such matters is some kind of an elusive higher (or perhaps lower) Logic, uncontaminated by the imperfections associated with the human thinking process. A logical framework that is free from the constraints of time and space. The question here is can we modify our existing reasoning so it becomes good enough to analyse the secrets of the universe? Is it even possible?