 We can say that non-culpable ignorance is chancy lucky when an agent fails to know that p (where p is significant for her), lacks direct control over whether she knows that p, and in a large proportion of nearby possible worlds does know that p. Lets say I drop my daughter Maya off at a friend’s house for a play date. She has a peanut allergy and I forget to inform the other parent, Dolores, at the time of drop-off. When I get to the coffee shop, I realize this and immediately text Dolores about the allergy, but because I’m in a “dead zone” the message does not go through. Not having received my text, Dolores proceeds to give the kids a snack with peanut butter in it, resulting in Maya having a near-fatal reaction. Dolores’ non-culpable ignorance in this case is chancy lucky since in a large portion of nearby possible worlds she would have received the text. The 16th century surgeon example, on the other hand, is better seen as an example of non-chancy luck, since his ignorance is the result of bad luck inasmuch as beliefs about germs vary across agents in different historical periods (the relevant reference group here), rather than nearby possible worlds. 