St Thomas speaks of a general and ordinary necessity, e.g., of food for the individual, of the union of the sexes for the race, not of an accidental necessity, or particular emergency. To extend the aphorism to the latter case would make it into an assertion of the end justifying the means, a doctrine read into the utterances of Catholic authors by persons who in malice or ignorance misconstrue passages like the present.

Of God and His Creatures: 3.147