Why do scientific experiments require 'stripping hypotheses' to validate principles?

Hello, this is an interesting question. I'll try to explain it with a real-life example, which might make it easier to understand.

Imagine you want to figure out: "If I add yeast, will the bread definitely become soft and fluffy?"

This is a great hypothesis. But what if, when you're baking bread, you add yeast, baking powder, use high-gluten flour, and knead the dough vigorously for half an hour, and the resulting bread turns out very soft and fluffy?

Now the question arises: Is the bread fluffy because of the yeast, the baking powder, the type of flour, or your kneading technique? You can't be sure.

That's because you've mixed several assumptions that "could make the bread fluffy" (yeast, baking powder, flour, kneading) all together.

What "stripping away assumptions" does is separate these things one by one.

To verify the core principle of "yeast," a rigorous chef (or scientist) would do this:

1. Prepare two identical batches of dough: The same flour, same water, the same temperature, kneaded for the same amount of time. Ensure all conditions are exactly the same, except for "yeast."
2. Add yeast to one batch (experimental group), and don't add it to the other (control group).
3. Then, let them ferment and bake in exactly the same environment.

Finally, if the bread with yeast becomes soft and fluffy, while the one without remains dense and hard, you can confidently conclude: Yes, yeast is indeed the key reason for the bread's fluffiness.

You see, in this process, we've "stripped away" all other assumptions (variables) like "baking powder can also make it fluffy" or "high-gluten flour is key," leaving only "yeast" as the changing variable.

Why go through all this trouble?

Because science aims to find definite, singular causal relationships. We don't just want to know "what works," but also "why it works," and "whether it's truly the factor at play." If you don't strip away other assumptions, your results might just be a coincidence, or a mixed effect, and you'd have no idea what the true "first principle" is.

In essence, this is a "controlled variables" way of thinking, ensuring you're not deceiving yourself. By creating a pure environment, you let the principle you want to verify "perform" on its own, to see if it truly has the effect you imagine. Conclusions drawn this way are the most reliable and closest to the truth.