Help me create a concise motto on science.

changing one's worldview based on credible evidence. "If the glove does not fit, you must acquit." This is maybe too glib of an answer, but this is as simple and as accurate a summation of science as you are going to find. You got to hand it to Johnny Cochran. Faced with gobs of scientific evidence, he took the core basic principle of scientific method - that theory must be supported by experimental result - and used it to turn the evidence to his advantage. If even one valid experiment produces an result contrary to the theory, the theory - however appealing - has to be wrong.

"Beauty and elegance" Paul Dirac had an idea that any mathematical or scientific theory requires 'beauty and elegance'

http://royalsociety.org/Nullius-in-verba/, linked to by http://ask.metafilter.com/155601/Latin-translation-of-I-remain-skeptical#2231176 in response to an earlier AskMe question, discusses Royal Society's motto, and lists some of the phrases that were considered. I like omnia probate "test everything" and nullius in verba "on the words of no one" (the one they actually use).

Ah yes, I meant to include "Nullius in verba" as the closest existing motto to what I'm seeking. Now if there was a clever way to combine that with the alternate sentiment, something like "Only on the word of nature".

What would the Latin translation be for "Start by admitting you might be wrong"? That's how I think about science.

Omnia probate is, if you take it in isolation and weigh it, about equivalent to your "Nothing without proof, all things with proof." It means "test everything," but also "test everything" / "test all things" - implying both skepticism and openness. (The Latin stem proba- is the origin of English words 'proof" and "probability.") A slight variation of this phrase might be more explicit: omnia probanda sunt "everything / all things are to be / should be tested / examined / proven." This can be shortened to omnia probanda "everything to be tested" - the ambiguity is the same as in English - or probanda omnia "to be tested - everything." Now if there was a clever way to combine that with the alternate sentiment, something like "Only on the word of nature" I can't come up with a succinct way of saying that in Latin. Everything I can think of is awkward, and I don't want that to end end up on anybody's arm or body. Maybe somebody else can.

Probare has http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0060%3Aentry%3Dprobo that won't help you. Not always straightforward, Latin. (I saw OJ "try on" that glove. Please. Like my child putting on mittens when she was three. Half on half off. They fit, you just had to tug.)

http://www.perseus.tufts.edu/hopper/morph?l=expertus&la=la might be better than probare. As in omnia expertanda?

Oops, *experanda. No "t."