A man is free to do what he wills, but necessitated to do what God wills.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“In this sense, liberty is consistent with necessity; for instance, water necessarily flows down hill when there are no impediments to its motion, and when, therefore, according to the definition, it is free. A man is free to do what he wills, but necessitated to do what God wills. All our volitions have causes, and are in this sense necessary. As for the liberty of subjects, they are free where the laws do not interfere; this is no limitation of sovereignty, since the laws could interfere if the sovereign so decided.” source