I'm not going schizophrenic. You tell me.

Everyone knows Alexander Hamilton was real. He has a Wikipedia page, he's on the $10 bill, Lin Manuel Miranda wrote and played him... HE MUST BE REAL. We learn about him in US History and some law students persevere through the entire Federalist Papers which he wrote under a pseudonym. We know what Hamilton looks like because of a painting by John Trumbull which was based on a bust by Giuseppe Ceracchi. Is someone real just because other people say he was?

If Hamilton was only mentioned by one person, that could have been easily made up. But he's referred to by the other founding fathers, his letters to his wife/secret lover remain, and institutions he founded (financial system, US) still exist. Is that enough to show he was real? Romulus and Remus must have had something similar but were they truly real or invented ex post facto? It's hard to tell.

It's easy to rationalize inventing a person. For Hamilton, the United States has a strong incentive to have a founding myth to spur nationalist behavior from their citizenry, which increases civic virtue. Hamilton is an inspiring model of an American citizen and statesman, despite some moral difficulties. He could totally be as real as Walter White, invented to brainwash the American public.

One of Hamilton's boys was John Jay, the first chief justice of the Supreme Court. We hear about the Supreme Court all the time, from New York Times articles to videos of funny justices at their alma mater. Are we 100% certain those people aren't actors?

I haven't seen the justices arbitrate in person; the public is blocked from attending in-person or seeing recordings. Our only evidence are written opinions and oral arguments both of which can be easily fabricated. A single unelected bureaucrat can easily be making all the decisions and hiring actors to display a theater of a strong judiciary. How will we know? Even if I saw them adjudicate in person, it could still be theater.

I know what the US flag looks like and how the national anthem sounds from my kindergarten programming. I've seen the centrally-designed buildings in DC. But is the country as it is marketed to me real? I've never seen the president in person. Elected officials are constantly brawling on Twitter—I've met some in person—but are they real or just actors? Russian elections show an obvious sign of doctoring, which we love pointing out. But how confident are we that our vote is actually counted and computed to choose a "president?" What if our elections just have a better randint() function?

We hear the US is at proxy war with Iran, Russia, and China from the media and from executive press releases. Our elected and technology leaders tell us that China is bad. What makes China different from Oceania? I've never been to China. I've met people who sound Chinese, speak Chinese, and say they are from China. Is that enough evidence to confirm China is real? Have you ever verified a "Made in China" label came from China? Just think about that. It may just be an invention meant to distract the citizenry from civil liberties violations and justify foreign invasions.

This epistemic uncertainty goes even deeper: I have a mom and dad. How do I know they are 100% my parents? My memory makes me think that I grew up with them. They have introduced me to many relatives. I share features with both of them and people we meet often say I look like my parents, but that can easily be biased because they were told we are related. I've never done a DNA test. I've seen my birth certificate but it could easily be forged. I don't remember anything before age five and I can't visualize any early memory of them. At what point did "mom" and "dad" become labels I accepted rather than verified?

Everything before this was built on the axiom that what you observe is true. I'd question that. When I look around, I see buildings made of stone, tables made of wood, and furniture made of leather. How do I know they are real? Is it leather just because it looks and feels like leather? How do I know I'm not being electrochemically stimulated in an interrogation chamber or incepted in a dream?

You can't be 100% certain of anything in your observed phenomenon. We update our beliefs as we collect more information, for example, when you fall on the concrete, your mind remembers it is hard. With that information, you will probably avoid falling and hurting yourself. The issue is that we don't differentiate from first-hand and second-hand information. Hitting concrete and trusting the NYT telling you COVID-19 broke out are two very different things.

Trust is a wager under uncertainty, not a belief under certainty. Even if you confirm the sources for yourself first-hand, there is a limit set at the phenomena we observe, which has its own (extreme) uncertainty.