[REGL] Pooh,
There is a tradition in the West which dates back at least to the time of Augustine of Hippo, that there are times when a kingdom or civil government should tolerate acts which are morally wrong, because not doing so would bring about some greater evil. This argument was made explicit by the theologian and philosopher Thomas Aquinas,
Now human law is framed for a number of human beings, the majority of whom are not perfect in virtue. Wherefore human laws do not forbid all vices, from which the virtuous abstain, but only the more grievous vices, from which it is possible for the majority to abstain; and chiefly those that are to the hurt of others, without the prohibition of which human society could not be maintained: thus human law prohibits murder, theft and such like.
http://www.newadvent.org/summa/2096.htm#article2In the context of the question of whether it was proper to tolerate the practice of Judaism, which Thomas held to be proper, he famously quotes Augustine's assertion regarding prostitution. Augustine says (De Ordine ii, 4): "If you do away with harlots, the world will be convulsed with lust."
I bring this up because this very argument was used by the former Governor of New York, Mario Cuomo. It should be noted that in doing so he was contradicting the statements of Catholic teaching on the subject of abortion and infanticide dating back at least to the second century. Nonetheless he did make this argument. It might grant his position more substance to note that it is not uncommon for those who hold something like the pro-life view to make an exception for women who have been raped, or in cases of incest. The argument in that case would be that, by forcing a women who had become pregnant because of rape to carry the child to term, one would be further depriving her of the freedom and autonomy which aught to be a birth rite for all people.
There are other situations where this line of reasoning is more compelling, as in the establishment of needle exchange facilities for those who use illegal drugs. By giving clean needles to the users of illegal drugs their unlawful acts are being encouraged, but at the same time the spread of deadly diseases is being thwarted. Mike Pence, at one time rejected the idea that needle exchange programs were good policy, until a massive outbreak of H.I.V. cases gave him cause to rethink his position.
https://www.nytimes.com/2016/08/08/us/politics/mike-pence-needle-exchanges-indiana.html
Edited 4/20/2018 02:28:57