Though the mills of God grind slowly, yet they grind exceeding small; Though with patience He stands waiting, with exactness grinds He all. - Henry Wadsworth Longfellow
It is to these two discoveries by that we owe the exactness of modern astronomy. .... This double service assures to their discoverer the most distinguished place (after Hipparchus and Kepler) above the greatest astronomers of all ages and all countries. Jean-Baptiste Joseph Delambre - Bradley
Words are made for a certain exactness of thought, as tears are for a certain degree of pain. What is least distinct cannot be named; what is clearest is unutterable. - René Daumal
It is the mark of an educated mind to rest satisfied with the degree of precision which the nature of the subject admits and not to seek exactness where only an approximation is possible. - Aristotle