A Thought about Two
Think of the number 2. What is it?
It is certainly not this,
2
or this,
two
Those are representations of what we call two, representations in a specific language and a specific numbering system. The real 2 is only in your head and mine, and everyone else who is aware of 2. We could say it's a concept we taught ourselves. But if it's something we just made up, would it tally so well with reality? Maybe we made a connection between two sheep, two fingers, and two fish, and put a label on that thing that made them similar. This thing we call two. Even if it's something we made up, it's something made to represent reality to us. We should still ask questions about what it represents.
So two is a universal concept that represents something to us about reality. Granted, though it is in reality, it's not something we can test for, we simply observe 'twoness' of certain objects. We can't define it as anything other than itself, but we recognize it when it's there. Two, as far as we can tell, is representing something fundamental.
There won't be a problem with two if it was only in our heads. The problem is the things we do with two. We build things in our heads with two and when we build them in real life, they work, thanks to two. Reality seems to agree with us that two is real as real gets.
But what is two?! I'm starting to get a headache, are you? Two is two. The answer points back to itself. It is a self-existent pillar of reality, needing no definition. It has no beginning (two was always two) and no end (two will always be two). All hail the two.
We did not, in fact, make up two, we only recognized it. In the same way, Newton did not invent or, in the strictest sense of the word, discover (cause everyone knew about apples falling before then), gravity. He discovered the law behind gravity. We discovered the law behind two. To claim to have made it up is to claim to have made up the universe. Either in the same way a fairy tale is made up or to have actually made it ourselves. Both avenues beggar belief.