Mental time travel is the ability to simulate alternative pasts and futures. It is often described as the ability to project a sense of self in the service of diachronic agency. It requires not only semantic representation but affective sampling of alternative futures. If people lose this ability for affective sampling their sense of self is diminished. They have less of a self to project hence are compromised as agents. If they cannot "feel the future" they cannot imaginatively inhabit it and hence their agency is compromised. The extent of such losses and consequent impairments to moral agency can be matters of degree.