Ultra posse nemo obligatory
The principle ultra posse nemo obligatur ( Latin : no one is obliged beyond ability) states that there cannot be a moral or legal obligation to perform which is impossible. This applies both if the performance is objective (= impossibility), i.e. for everyone, and if the performance is subjective (= inability), i.e. only impossible for the debtor . Another formulation is: Ad impossibilia nemo tenetur (no one can be forced into the impossible).
For German civil law , this principle is regulated in Section 275 (2) BGB for objective impossibility and in Section 3 for subjective impossibility. Impossibilium nulla est obligatio represents
a similar legal principle, which eliminates the obligation to perform in the event of objective or subjective impossibility by law ( ipso iure ) ( Section 275 (1) BGB).
However, the principle does not make any statements about possible claims for damages or the risk of price .
In criminal law, this idea comes into play in cases of negligence and omission offenses, for example through the justifying conflict of duties .
It also applies in administrative law to the question of whether there can be a right to action by an authority.
In ethics , the limitation of moral duties by what is feasible is the only way to infer from the factual to the normative without violating Hume's law . Such conclusions are, however, purely negative and cannot justify positive values or norms.
