“Ohne Hast, aber ohne Rast.”
Goethe’s motto, and usually translated as “Without haste, but without rest,” but that makes it sound like you shouldn’t snooze on the job every now and then (something most poets would disagree with). My sense is more “without faltering.”
Randell Jarrell had this motto on his desk while he was translating Faust, which I am trying to make it through for the umpteenth time.
A Few Reasonable Words 