Typography: So how many fonts can we have in a single article without compromising design?

Many, many years ago when I was doing a design course at college I was always told don’t use any more than two fonts, one for Headings and Subs and one for Paragraphs. Usually I try to stick to this principal.

however some times it looks better with more…

In my opinion design and for that matter creative work does not have to stick to rules, I mean the whole point is orginal work, so where do we draw the line?

There are rules for Fonts and Typography, Ratios and Colour do we need to stick to them.

Maybe we are making a statement by not! and maybe that in its own right will be a rule in the future?

As usual thoughts and input would be welcome…