"No one should suppose that the position advanced lends any support to the claim that scientists should be free to work with fetal tissue in research. It should be obvious that those who set up arrangements with Planned Parenthood or other abortion facilities to receive the remains of aborted children, so that they can be used in programs of experimental research, are doing something that cannot be justified under any principle of Catholic teaching. The direct cooperation between the parties in this matter sullies the hands of those who receive the fetal materials and makes them cooperators in the evil of abortion. In the case at hand, I am talking about the use of the cells that descend from an abortion, cells which replicate themselves in culture, from which vaccines are made. That product is then made available for use by physicians. The level of cooperation in the two cases is radically different, as the above brief rehearsal should make plain."