Nicholas Agar argues that we should avoid certain ‘radical’ enhancement technologies. One reason for this is that they will alienate us from current sources of value by altering our evaluative outlooks. We should avoid this, even if enhancing will provide us with novel, objectively better sources of value. After noting the parallel between Agar’s views and G. A. Cohen’s work on the ‘conservative bias’, I explore Agar’s suggestion in relation to two kinds of radical enhancement: cognitive and anti-ageing. With regard (...) to both, there are reasons to doubt Agar’s empirical predictions about the severity of the evaluative changes we will undergo. Nonetheless, there is some force to the argument as applied to cognitive enhancement; in particular, radical cognitive enhancement may endanger our current valuable relationships with our loved ones. However, even if we find this a plausible worry for radical cognitive enhancement, it is not plausible for even radical anti-ageing enhancement, because the change Agar predicts will not affect our core motivations in the way that cognitive enhancement threatens to. (shrink)