Take this tweet:
|'Grade' as in '7th grade' is not part of the English language|
So why on earth did he put it in such a stupid, guaranteed-to-cause-a-row way? Does he like getting into fights so much that even innocuous opinions must be stated in a controversial manner?
The bit I'm referring to, if it's not blindingly obvious, is the bit where he says that 'grade' is 'not part of the English language'. It... but... it... well, it obviously is. How can it not be? American English, or the collection of dialects of English spoken in that part of the world, are most definitely English. And if 'grade' (in this sense) is part of at least some of those dialects, then it is part of English.
It's possible that Dawkins was using some rather unusual definition of English. If you take any English speaker, let's say me, then we can agree that I speak English, I hope. And if you take another English speaker, let's say Richard Dawkins, then we can also agree that he speaks English. And so on and so on for any English speaker in the world. But our two Englishes are not precisely the same. In the case of me and Dawk, they're not far removed from each other. We're both speakers of British English dialects, although his is a bit more old-fashioned than mine. But if you compared Dawk and a teenage speaker of English from, say, California or South India or Grenada or Kiribati, then you're going to find a few more differences between the dialects. One might, then, wish to say that something is only 'English' if it is found in all dialects of English. This is a silly way to define English because it leaves you with about three words and a smattering of grammar and no sounds with which to pronounce them (I exaggerate, of course, but not much).
You can say the opposite, and say that something counts as 'English' if it is found in at least one English-speaker's dialect. But then you run into trouble defining English, as it can get a bit circular. You could also say that there is no such thing as English, merely a collection of idiolects (personal dialects) which converge with each other to a greater or lesser extent, some of which are mutually intelligible and some of which are not. Some people do say this, I think, but it's a somewhat extreme position to take. It's largely a philosophical problem, and for practical purposes one usually needs to define English in some partially arbitrary way. On any of those definitions, American English still counts as English and Dawkins is being a numpty.