According to Catholicism, is it sinful to physically harm abortion doctors to prevent them from performing abortions?

**Question:** Is it sinful to physically attack a doctor who performs abortions and break his fingers so that he can not perform an abortion? If yes, why? If no, why? Does it depend on the circumstances? **Arguments against:** 1. It would seem that one should not attack a doctor because he is not doing something unlawful. 2. It would seem that one should not attack a doctor because one does not have the authority to exert violence. However, these arguments seem not to be good. To explain why I will give an analogy. Imagine a situation where some guy wants to dismember a 3-year-old child. You see him going toward the child, and you know for certain what he plans to do. You are able to stop him via violence (and no-one except that guy will be harmed in the process). However, your stopping him will be illegal. It still seems that you should stop the guy. This analogy seems to explain why neither authority nor what is (il)legal matter, and therefore it shows why arguments against are not good arguments. Also, it is often said that: "Necessity does not know the law." And that "Unjust laws are not really laws." 3. If it were not sinful to attack a doctor who performs abortions someone would already be doing it. But we did not see such a case. **Arguments for:** 1. Using the same analogy as above, it seems not only that it is not sinful to attack a doctor, but that we have a duty to attack a doctor, just as we would have a duty to stop someone (if we are able to) who wants to dismember a 3-year-old child. Maybe the arguments above depend on whether we see a doctor who directly goes to the hospital to perform an abortion, but not to a doctor who does not directly go to perform an abortion. I am interested in responses from a Catholic viewpoint (preferably a natural law response).