Joe Moran, First You Write a Sentence, (p.190):
Every typographer understands that the space between the type matters as much as the shapre of the letters themselves. The letter-carver David Kindersley said that “a bad space is worse than a bad letter.” How much of a gap you leave between the letters, between the words, between the lines, between the paragraphs: it all matters beyond words. Space makes the reader feel cared for, even if she can’t put her finger on why. The way the writing looks is also what is says.