 Thus, entity realism sometimes is also called instrumental realism or experimental realism.While many philosophers acknowledge the intuitive pull of entity realism, it has also been strongly (some would say conclusively) criticised, both as being too restrictive (in that it ignores entities that are observable yet do not lend themselves to manipulation) and as being too permissive (to the extent that seemingly successful instances of manipulation may turn out to be spurious).Stathis Psillos remarks that entity realism is indeed a realist position (since it defends the reality of unobservable entities), but it is a selective realist position, since "it restricts warranted belief to entities only, and suggests to fellow realists that they are wrong in claiming that the theoretical descriptions of these entities are approximately true."