 For the two theories share a commitment to  Most Reason to Desire  in that they are both act-consequentialist theories, broadly construed. That is, they both hold that whether an agent ought to perform an act is determined solely by whether that agent ought to prefer its outcome to those of the available alternatives. It’s just that whereas the ethical egoist holds that agents ought always to prefer that they themselves have more hedonic utility, the utilitarian holds that agents ought always to prefer that there is more hedonic utility overall.