In any event, the person who finally classifies and describes a species has the task of taxonomic circumscription. Circumscription means in essence that anyone competent in the matter can tell "which creatures are included in the species described, and which are excluded". It is in this process of species description that the question of the sense arises, because that is where the worker produces and argues his view of the proper circumscription. Equally, or perhaps even more strongly, the arguments for deciding questions concerning higher taxa such as families or orders, require very difficult circumscription, where changing the "sense" applied could totally upset an entire scheme of classification, either constructively or disastrously.