Words to use carefully

Today I found myself talking about the writing centre to a group of postgraduate students. In the interest of being direct, I decided not to use speaking notes. An odd word choice here or there, I thought, was worth it if I could maintain eye contact throughout. Usually that would be the right choice, but today I had the unpleasant experience of catching myself saying something I definitely didn’t want to be saying. See if you can spot the moment when my nose started to wrinkle:
You shouldn’t see the writing centre as remedial. Even the strongest writer in this room can benefit from listening to what someone else has to say about their essay. As proof, consider the academics in our department. Even those who have been publishing for decades are glad to get outside opinions. Nearly every journal article they write includes a long list of people who helped make the writing better.
It wasn’t the use of singular “their” that made me shudder (it’s absolutely unproblematic here; ignore anyone who tells you otherwise). No, the word that troubled me was “proof”. In an academic context, “proof” and “prove” have very specific meanings, and are rarely, if ever, applicable outside of a paper on mathematics or logic.  While a brief speech is not exactly a journal article, I still should have used the word “evidence” instead. I had a choice: I could correct myself in an apologetic way (I am Canadian, after all) or I could simply move forward and hope nobody noticed. “Look confident”, I told myself and chose the latter. I continued to talk for a few more moments before remembering that my audience included professors who spend (part of) their professional lives talking about evidence for claims and chastising students for calling that proof. Whoops. This isn’t a quibble — evidence plays an essential role in scholarly work, and if you mislabel it as “proof”, you look like a rookie. Evidence and proof are fundamentally different things. Evidence can be used to justify your belief in something, while proof demonstrates that something is necessarily true. Evidence doesn’t magically become proof if you find a lot of it. Nor does it become proof if you successfully undermine what your opponents have to say. The best option for most students is to examine each use of “proof” or “prove” carefully before submitting.  When you prove something, you show that it absolutely must be true; the proof is the final word on the topic. For instance, if a and b are consecutive integers, you can prove that their sum must be odd (if b = a+1, then a+b can be rewritten as 2a+1, and since 2a must always be even, 2a+1 must always be odd). In other words, you don’t need to ask yourself if something counts as proof or evidence. If it’s proof, you’ll know it. For another example, you can look at Turing’s proof that the Halting Problem is undecidable. If that sounds indigestible, try Geoff Pullum’s reworking of the proof in the style of Dr. Seuss. Now, there are legitimate ways in which “proof” and “prove” might be used in an essay.  You could certainly write about the “burden of proof”, for instance, or a “proof of concept”.  You can say an idea proved to be a good one, and you can point out that correlation does not prove causation.  And I would say that you could prove that something works with a test run. The problem is that it can be difficult to fight off the urge to use “proof” and “prove” to mean “evidence” and “supports the idea that” when you see sentences like these in the newspaper: “Scientists prove that truth is no match for fiction on Twitter” (The Guardian) “There’s now proof that swearing makes you stronger” (BBC) “Scientists find proof that privatising fishing stocks can avert a disaster” (The Economist) What to do? It’s pretty hard to change the way you talk. But you can always comb through what you write for accidental lapses. Try using your computer to search through your writing for “proof” or “prov” (leave out ‘e’ so that you catch “proving” as well).  Each time, consider whether it might be better to use “evidence”, “supports”, or something similar. But while you’re at it, run a search on Google Scholar as well and look at some of the misuses of these words that have managed to sneak into published academic articles. And breathe a sigh of relief with me.