My reading of the quote is that empiricism is superior to rationalism (the old philosophical schools, not the sort we discuss here). If I have a proof that my bridge will hold a thousand pounds, and it breaks under a hundred, then the experiment trumps the proof.
If I have a proof that my bridge will hold a thousand pounds,
By "proof", do you mean experimental evidence, or armchair rationalization?
Here's the new thread for posting quotes, with the usual rules: