Final answer:
False. It is not necessary to believe that all abortions are permissible if one believes that some abortions are morally permissible.
Step-by-step explanation:
False. The statement posits that if someone believes some abortions are morally permissible, then they must believe all abortions are permissible.
However, this is not necessarily true.
People can have differing opinions on the moral permissibility of different types of abortion based on various factors such as fetal development, viability, and the rights of the pregnant person.
One example is the Supreme Court's ruling in Planned Parenthood v. Casey, which allows for the regulation of abortions based on fetal viability. So, it is possible to believe that some abortions are morally permissible while also believing that not all abortions are permissible.