Only ignorance makes us think that we can alter the future
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“But, you may retort, we are surely right in being more concerned about future misfortunes, which may possibly be averted, than about past calamities about which we can do nothing. To this argument Spinoza’s determinism supplies the answer. Only ignorance makes us think that we can alter the future; what will be will be, and the future is as unalterably fixed as the past. That is why hope and fear are condemned: both depend upon viewing the future as uncertain, and therefore spring from lack of wisdom.” source