The em dash is the most beautiful punctuation mark, all the more because it is rare --- and it is best kept that way. Certainly a sentence with more than two is imparsible. In fact, more than a few in a whole article is probably getting annoying. It's like the exclamation point in that way.
Once you discover the em dash, it is hard to restrain yourself. But I'm trying to come back to the comma. It does its work without fanfare, almost invisibly. The mature writer realizes his job is to tell the reader something without getting in the way.
I land on the side favoring a space on each side of the dash. Unconventionally, I prefer to ASCII-encode my em dashes with three hyphens. The traditional two aren't long enough. But two is better than one. I always have to reread sentences by someone who thinks the hyphen and the dash are the same thing.
Once you discover the em dash, it is hard to restrain yourself. But I'm trying to come back to the comma. It does its work without fanfare, almost invisibly. The mature writer realizes his job is to tell the reader something without getting in the way.
I land on the side favoring a space on each side of the dash. Unconventionally, I prefer to ASCII-encode my em dashes with three hyphens. The traditional two aren't long enough. But two is better than one. I always have to reread sentences by someone who thinks the hyphen and the dash are the same thing.