I explore and defend the unusual view that the replacement of matter taking place in the human body undermines egoistic reasons, and that we therefore have little or no basis for long-term egoistic concern. I begin by arguing that you should not have egoistic concern for a replica, i.e. a person resulting from a complete and sudden replacement of matter. I then argue that when it comes to egoistic concern, replication is not relevantly different from the slower and more gradual form of replacement found in human metabolism: if the former undermines egoistic reasons, so does the latter. I grant that the resulting view is, in some respects, hard to accept, but I conclude that we should at least treat it as a serious possibility.
