"Should we regard something as valid even if we cannot prove it?"

http://theeuropean-magazine.com/263-heuer-rolf-dieter/788-science-and-the-public-sphere

"Progress Isn't A Linear Development"

by Rolf-Dieter Heuer — 06.08.2012

With the discovery of the Higgs boson, the last gap in the "Standard Model" of physics has been filled. Martin Eiermann talked with the head of the CERN laboraties, Rolf-Dieter Heuer, about the future of physics, the value of diversity, and the difference between knowledge and belief.

"The European: That brings us back to the differences between the natural sciences and the humanities. A philosopher might say: what matters is the internal coherence of a theory.
Heuer: That is precisely one of the problems we have to discuss. Should we regard something as valid even if we cannot prove it? It’s an exciting point of contention where the physicist might reply: “anything that cannot be proven remains a theory.”

The European: And the theologian answers, “I know because I believe.”
Heuer: Do I know something because I believe? Or do I believe what I believe? You see, you are talking about the nature of knowledge itself, and about the differences between knowledge, faith, and feelings. When should we speak of “knowledge”? I am very curious about the answers we might get."