Limits to Man's Power

Consequently, unless we are willing that the responsibility of procreating life should be left to the arbitrary decision of men, we must accept that there are certain limits, beyond which it is wrong to go, to the power of man over his own body and its natural functions—limits, let it be said, which no one, whether as a private individual or as a public authority, can lawfully exceed. These limits are expressly imposed because of the reverence due to the whole human organism and its natural functions, in the light of the principles We stated earlier, and in accordance with a correct understanding of the "principle of totality" enunciated by Our predecessor Pope Pius XII. ²¹