Matthew Carter on typography from an email to Paul Felton.

Book: The Ten Commandments of Typography by Paul Felton. New York, 2006, Merrell Publishers Limited.

How important do you think the main typographic 'rules' are, and should they always be followed?

The advantage of rules is that they can prevent mistakes; the disadvantage is that they can prevent discoveries. When I started work in a type foundry fifty years ago my efforts as a learner consisted entirely of mistakes. This was pretty discouraging, but an experienced workman told me, "Always look carefully at a mistake before you discard it - it might be better than what you intended". I think there's more to the design process than simple trail and error, but errors are often the price paid for successful trails, and rules learned by rote are valuable only if they are constantly questioned.