Counterfactual: the theory of evolution is one of the most successful scientific theories, yet it contains no equations; nor numbers. It is rather a framework of ideas in which observations can be made sense of.
I tend to agree with you that numbers are inessential in a scientific theory, and that Darwin's theory is a good example of this. But your critics also have a point that some nice math has been added to the theory since Darwin's time. (Not enough of a point to justify downvoting you, though, IMHO).
As a smaller scale example of a non-numerical scientific theory, consider the theory that the historical branching order of the Great Ape family tree is "First orangutan, then gorilla, then man, leaving the two species of chimp." That is a meaningful...
This is our monthly thread for collecting these little gems and pearls of wisdom, rationality-related quotes you've seen recently, or had stored in your quotesfile for ages, and which might be handy to link to in one of our discussions.