Demandingness objections have become a stock argument in ethics claiming that single moral demands or entire moral theories must be given up or altered if they ask too much of agents. But can we clearly distinguish an acceptable level of demandingness from one that is too high? I argue that demandingness objections inevitably fail to make that distinction without borderline cases because they are sorites-susceptible.
First, I show that the heap paradox applies to demandingness objections and the expression “overdemanding” because two conditions are met. There is an ordering of values on one dimension decisive for the expression’s application: the cost to the agent. Also, the expression “overdemanding” is tolerant, because the difference between two neighbouring levels of demandingness is so small that it does not allow us to say that this is the difference between an acceptable level of demandingness and critical overdemandingness.
Second, I discuss attempts to overcome or bypass the vagueness of demandingness objections. I will argue that these strategies are not very promising and that we should rather embrace the vagueness.