Longtermism is, very roughly for now, the thesis that most of the value of our actions lies in the far future, so that considerations of the very long run are the primary determinant of which action is optimific, in a wide class of decision situations. If some such claim is true, it has potentially widespread practical significance. In both small-scale and large-scale decision making contexts in both the private and public spheres, the standard practice is to assume (or otherwise believe) that attempting to influence the course of the very long-run future would be intractable, so that we should instead focus on more immediate consequences. In this talk, I will attempt to articulate a plausible longtermist claim, set out as clearly as possible the case for thinking that the claim is true, and examine the extent to which the claim can be defended against various empirical, axiological and decision-theoretic assumptions.
March 20, 2019, Groningen: 2 lecture events at the Centre for PPE with Hilary Greaves (Oxford)

Longtermism is, very roughly for now, the thesis that most of the value of our actions lies in the far future, so that considerations of the very long run are the primary determinant of which action is optimific, in a wide class of decision situations. If some such claim is true, it has potentially widespread practical significance. In both small-scale and large-scale decision making contexts in both the private and public spheres, the standard practice is to assume (or otherwise believe) that attempting to influence the course of the very long-run future would be intractable, so that we should instead focus on more immediate consequences. In this talk, I will attempt to articulate a plausible longtermist claim, set out as clearly as possible the case for thinking that the claim is true, and examine the extent to which the claim can be defended against various empirical, axiological and decision-theoretic assumptions.