Many years ago... Like, centuries ago, back in 1641, Rene Descartes rationalized his way to a frightening conclusion... that he may not exist. Upon further thinking, he started questioning what we really know for certain.
I don't think we really know anything for certain.
In my opinion, I don’t think you can ever find certainty when inquiring about the natural world. In fact, I think that we just have to focus on being less wrong, instead of more right. When we look at the natural world, nothing has really been proved, it’s just been tested in a few scenarios and it works. We know that our most basic assumption isn’t always going to be the correct one when it comes to the certainty of the natural world.
As we’ve seen in science, and in the real world, this isn’t always the case. In the early 1840s, menstruating women were being locked up in asylums due to misconceptions and fake science that allegedly proved that their uterus was trying to escape. We now know that that isn't the case, but back in that era, it was considered factual. Those of us that are so certain in science, really shouldn't be. While it is the best we have at the time, we can never be 100% certain that it will always be correct.
Secondly, there is no certainty for how people will be treated by others, really there is no certainty in the human world. It all relies on randomness, and there is no way to predict another human's actions. For example, in a world where xenophobia unfortunately exists, people jump to conclusions, stereotype and create assumptions about others based solely on their culture or religion. We see this segregation being made towards people of colour, including Muslims for their culture, and African Americans for their race. Although this is our gut assumption, because of the world many of us grew up in where we were taught inadvertently where different peoples' places were based on the way they looked / where they were from. Unfortunately, this is the manner that the idols of the tribe fit into the human world, and there is absolutely no certainty.
Another thing that impacts our knowledge is our mental biases. They can cause us to attempt to validate our beliefs by any means and in the meantime attempt to invalidate another's belief if it is contradictory to our own. Many people that have been vegetarians since birth have a prejudice against meat, usually through beliefs that were handed down to them from their parents. This particular example perfectly demonstrates what the idols of the cave are, as it shows how the vegetarians' nature is to be prejudiced against meat since it’s their belief that being a vegetarian is better.
In a way, everything is true until we disprove it. Descartes believed that without separating ourselves from our old ways, we cannot embrace the new. We see this in politics quite often. Because someone in power defends an idea, if they seem knowledgeable on the topic, the masses will accept it without questions. This applies specifically to this question in the natural world as I mentioned before, if a scientist says that they have created a cure for a disease, and the government signs off on it, the masses will accept it with little questioning. This is largely due to the idea that the scientist and the government are more knowledgeable than the person, and so if the party that allegedly knows more approves it, the masses don’t need more evidence to approve it as well.
Once again, this mentality can come into play with the human world too. If we look at the opposite conflicting spectrum of Descartes views, empiricism, we can understand how the majority of our knowledge may not actually come from our rationalization, but our experiences. However, while deriving knowledge from experience makes sense, it doesn’t ensure certainty since it doesn’t account for the human element, the cultural element, and just the overall differences that we see in different societies. Because of that aspect; that element of unpredictability. In part, this is because many organic actions cannot be repeated exactly the same way multiple times. Our bodies do not sleep the same way every night, we do not eat the exact amount of the exact same thing every day, we do not produce the same amount of waste at the same time every day. This fact alone makes it hard to do an empirical observation and come to a conclusion based solely on experiences.
In conclusion, I don’t believe that anything is for certain, regardless of whether it is part of the natural world or the human social world, I don’t think we can ever be right, we can just be less wrong. Science in the natural world is continuously changing and adapting to new technologies, and all of those technologies are uncovering things that we never knew, and are disproving theories that we very strongly believed were true. On the other hand, in the social world, the majority of our everyday actions cannot be perfectly duplicated, and there is an element of randomness to human behaviour, which is why I don’t believe that it is 100% predictable or certain.