Speaking of Romans:
The origin of our word "soap" almost certainly comes for the name of Mount Sopa just outside of the city of Rome.
2000 years ago, Roman women would wash their clothes in the streams that ran off of Mount Sopa after a rain because doing so would get their clothes cleaner than washing them in any other stream or river at any other time.
Nowadays we understand that the reason for this was because Mount Sopa was also the place where Romans would go to make sacrifices to their Gods. Vendors at the base of Mount Sopa would sell small animals and birds to be used as sacrifices to the the God's favour in granting a request. Romans would burn a pidgeon (for example) to ask the God's to ensure their decision to sell their cart is a good one. They might burn a whole lamb to ask the God's favour in ensuring their daughter's marriage is a success.
So, the fat melted off the sacrificial animal's body would mix with the alkaline ash from the wood burned to sacrifice that animal to form a crude kind of soap that would dissolve in the waters that ran down the slopes of Mount Sopa after a rain. It is this dissolved soap that existed in the water of the streams running down Mount Sopa after a rain that was responsible for the fact that clothes cleaned in those streams came out significantly cleaner.
This Earth we live on doesn't come with a User's Manual. We have to learn every thing the hard way... by observation. Whatever doesn't agree with oberserved result must therefore be theoretically wrong, and we have to modify our theory in order for our predictions to agree with what we observe through experimentation.
It's this test of whether or not prediction jives with experimental results that drives the science we call "research". It's only through that research that we actually learn anything about the world around us.