> Is causality really a fuzzy concept? For example I assume if action A causes event B I assume the connection is 100%. Can we really say that action A has a 30

> Is causality really a fuzzy concept? For example I assume if action A causes event B I assume the connection is 100%. Can we really say that action A has a 30% chance of causing event B? The world is probabilistic at the quantum level so I don't see how it could be otherwise. > I ask because the more I think about it, when someone says action A causes a 30% chance of event B occurring what he is technically saying is action A is one causative factor that must occur and that we're missing information about other causative factors. To my knowledge this has been physically disproven: https://en.wikipedia.org/wiki/Hidden-variable_theory#Bell's_theorem https://en.wikipedia.org/wiki/Hidden-variable_theory#Bell's_... (Note I'm just responding to your philosophical question, not the biological one. In particular I'm not suggesting anything about the practical relevance of quantum effects to the biology discussion here, or lack thereof.)