People who like animal products but believe it is wrong to consume them are often so demoralized by the apparent inefficacy of their individual, private choices that they are unable to resist. Although he was a deontologist, Kant was also aware of this ‘consequent-dependent’ side of our moral psychology. One version of his ‘moral proof’ is designed to respond to the threat of such demoralization in pursuit of the Highest Good. It provides a model for a contemporary, secular argument regarding what is permitted in order to sustain resolve in contemporary industrial contexts (like that of industrial animal agriculture). The argument’s conclusion is that one of the things we can rationally hold, as an item of defeasible moral faith, is a certain decision-theoretic principle regarding what it is to ‘make a difference’.