Type Is a Carrier of Information, Not Decoration
Spiekermann's most core belief is that typeface selection is not a matter of aesthetic preference but of information efficiency. The wrong typeface makes information hard to read, hard to understand, and can even create wrong tone associations. The right typeface should be 'invisible' — letting readers understand content effortlessly without noticing the typeface itself. This principle runs through all his typeface design and brand design work.
Source: Stop Stealing Sheep & Find Out How Type Works by Erik Spiekermann and E.M. Ginger, 1993
