Maurice Allais Quote

Any author who uses mathematics should always express in ordinary language the meaning of the assumptions he admits, as well as the significance of the results obtained. The more abstract his theory, the more imperative this obligation.
In fact, mathematics are and can only be a tool to explore reality. In this exploration, mathematics do not constitute an end in itself, they are and can only be a means.

in La formation scientifique, Une communication du Prix Nobel d'économie, Maurice Allais, address to the Académie des Sciences Morales et Politiques (1997).