"Scandal is a theological concern in the sense that its technical meaning involves leading someone to sin or causing confusion as to what is a sin. Even apart from the matter of sin, awareness of the significance of one’s actions relative to the moral instruction of others has special relevance to the question of vaccinations, which is a concern primarily for parents. That is to say, if parents endeavor to teach their children that some actions, such as abortion, are bad in principle, they need to consider carefully whether the use of certain vaccines does not constitute a source of confusion for their children, who might at some point become cognizant of the factual dependence of some vaccines upon voluntary abortion. Can one coherently and plausibly defend the view that abortion is bad in principle and that yet the use of these vaccines is good? Can one teach one’s children to understand this, or will it happen that they will understand the actions of their parents to belie their words? Will the lesson that is actually learned be that abortion is usually wrong, but sometimes it is beneficial, and that parents who try to hold otherwise are deluding themselves?"