Authors:

If you assume continuity, you can open the well-stocked mathematical toolkit of continuous functions and differential equations, the saws and hammers of engineering and physics for the past two centuries (and the foreseeable future).

Benoit B. Mandelbrot, Richard L. Hudson (2010). “The (Mis)Behaviour of Markets: A Fractal View of Risk, Ruin and Reward”, p.86, Profile Books
If you assume continuity, you can open the well-stocked mathematical toolkit of continuous functions and differential equations, the saws and hammers of engineering and physics for the past two centuries (and the