Contraception

The prevention of conception by unnatural means takes many forms. Strictly speaking, contraception refers to the attempt to keep sperm from fertilizing eggs, or ova. Spermicides, barrier methods (condoms & diaphragms), cervical sponges and caps, and withdrawal are, strictly speaking, true contraceptives. They are unnatural by definition in that the sexual act is inherently procreative, or at least should not be altered in such a way as to prevent the natural consequence of possible pregnancy.

The intrauterine device (IUD) can act contraceptively by impeding the transport of sperm to the fallopian tubes. The IUD also can act to prevent a conceived baby from implanting in the uterus, which would be a very early abortion. This is called an abortifacient mechanism.

The Pill may act contraceptively, but it also is designed to prevent the implantation of any possibly conceived baby from taking place, which is most definitely abortifacient. For more on this see the following sites:

American Life League
Pharmacists for Life (select "FAQ")
A Doctor Explains How the Pill and Other Contraceptives Work
The Pill

Sterilization is contraceptive in that it severs the passages through which sperm or egg would travel to each other. However, both vasectomy and tubal ligation violate the natural integrity of the body. When a healthy system is intentionally damaged for no proportionately serious medical reason, it is nothing less than self-mutilation.