Didn't we recently confirm gravitational waves by checking out a couple interacting black holes, originally theorized by Einstein 100 years ago? I think even Einstein would agree that it was much harder to discover it than to theorize it.
The experiment would never have been done without the theory, and a long line of experiments suggesting that Nature and the theory had a lot to do with one another, first. We knew that gravitational waves, or something very much like them, happened due to the binary pulsar work by Hulse and Taylor in 1974.
Einstein's advance was quite spectacular, and early.
Without the theory, how well do you think the funding submission for the experiment would have gone? Two laser interferometers a couple of kilometres long in specially built tunnels, with super sensitive custom equipment costing millions of dollars running for years just on the off chance? Sure, here’s the cheque!
So their method for finding the signal was to calculate the signal, then subtract it from the data and see if the residual noise looks like noise...how is that good science? It seems like it would be too easy to make your data fit the theory.
There is a cool documentary about how Einstein was trying to prove relativity theory, and it involved a lot of work, special telescope, traveling, war... I think it was done at third attempt.
Imagine if he would have died before proving it ...
My point is, he didn't stop in the theory, but also designed an experiment and worked a lot to get it proved.
Cajal's statement clearly doesn't apply to him.
I'll try to find the video, or if someone remembers please link it.
Tell that to Einstein.