There are four great sciences, without which the other sciences cannot be known nor a knowledge of things secured...Of these sciences the gate and key is mathematics...He who is ignorant of this [mathematics] cannot know the other sciences nor the affairs of this world.

Opus Majus [1266–1268], Part IV, distinction 1, chapter 1, trans. R. B. Burke, The Opus Majus of Roger Bacon (1928), Vol. 1