Robert Bringhurst
Definition.com
The Rule is there to be broken — By all means break the rules, and break them beautifully, deliberately and well. That is one of the ends for which they exist.
Definition.com
Typography is an art wherein space functions like time in music. It is infinitely divisible, but a few proportional intervals can be much more useful than a limitless choice of arbitrary quantities.
Definition.com
Typography is to literature as musical performance is to composition: an essential act of interpretation, full of endless opportunities for insight or obtuseness.