two sisters

I think of it this way.  The laws of the Church say you can't take contraceptives.  The laws of the land say that it's quite fine.

Now, until the Church is prepared to step in and bail me out if I'm caught speeding or not paying my taxes, I'm more inclined to listen to the laws of the land.

Besides, it's rather easier for the clergy to avoid pregnancies and even then, strange things happen... there are a remarkable number of immaculate conceptions...