Longtermism is the view that positively influencing the long-term future is a key moral priority of our time.^[1][2]

A distinction is sometimes drawn between longtermism simpliciter and strong versions of that view.^[3] While allowing that other forms of influence may also be important, strong longtermism holds that positively influencing the long-term future has dominant moral importance. This view has been defended by Hilary Greaves and William MacAskill,^[4] and has precedents in the work of Nick Bostrom,^[5][6] Nick Beckstead,^[7][8] and others.