大変面白い記事でした。
"Men have full control of whether or not they cause a pregnancy in that only a man can decide whether he's going to release sperm and where he's going to release the sperm. That's always his choice. And so if men didn't want to cause a lot of pregnancies, they could easily stop causing unwanted pregnancies."
確かに……。
後で、vasectomyについて調べてみようと思います……。 [参照]