The thread on mathematical typesetting software got me thinking about the general business of mathematical writing; here are a few thoughts for you to tear into at will.
Once upon a time - I know it's true, I read about it in history books - a mathematical manuscript would go through a couple of handwritten versions; the author would then pass the final draft to a typist, who would type all the words and whatever mathematical symbols she (it was usually a she) could find on her typewriter. Faced with complicated symbols or equations on separate lines, she would leave appropriate space. The author would then go through the typescript (plus the one or two carbons) and fill in the missing mathematics. So complicated mathematical expressions had to be dealt with quite separately from the main text.
Now TeX, on the other hand, enables the author to deal with the text and the mathematics at the same time, and I think that this might be the root of some of the problems which some people have with it. Typesetting a complicated formula in TeX takes time; rather more time, perhaps, than it took to type the previous paragraph of text. (This is my experience; I admit this may be down to my laziness with the typing tutor - I abandoned it as soon as I could type _words_ with fluidity, so consequently I'm great on the alphabetical keys but poor on /, #, ( and so on.) As a result, my own LaTeX output tends to be very wordy, with lots of short diversions into math mode ($x$, $y$ etc.) but few displayed-math formulae. (If I'm allowed to add a personal quibble here, it annoys me that TeX interprets blank lines as paragraph breaks: this prevents me from breaking up the TeX source as I'd like. Yes, I know I could comment out blank lines with a %, but there's a principle involved here, grumble, grumble. I'd prefer an end-of-paragraph marker a la HTML.)
Perhaps all I've said here is that TeX allows me to write bad mathematics (or mathematics badly). Any thoughts? In particular, is it a bad idea to compose in TeX rather than doing it in longhand first?