The terminology of “lives not worth living,” “worthwhile lives,” and “unworthwhile lives,” used by John Harris and many others, has become an accepted linguistic convention in bioethical discussions. These terms are used to distinguish lives of overwhelming negative experience from lives that are or are expected to be of overall positive value. As such, this terminology seems helpful in discussions around resource allocation, end-of-life decision making and questions of when it might be acceptable (and unacceptable) to reproduce. This paper argues that there is, however, a problematic ambiguity inherent in these general terms that is particularly evident when it comes to discussing reproductive choices. It is suggested that in this context, this ambiguity can conceal authoritarian eugenic motivations that are difficult to justify and that many using these terms would not adhere to. As a result, it is argued that we should replace these terms with the terms “intrinsically valuable” and “intrinsically harmful.” This would make it more explicit what exactly is meant and would allow these matters to be debated with greater clarity.