I fear that in this world one must be either hammer or anvil.

Voltaire (1694-1778) French writer [pseud. of Francois-Marie Arouet]

Philosophical Dictionary, “Tyranny” (1764) [tr. Gay (1962)]
    (Source)

Alt. trans.: "In this world we run the risk of having to choose between being either the anvil or the hammer." [Baskin (1961)]