I will deal with that issue at length a bit later today or sometime tomorrow.
Now, however, I'd like to point out to you Dr. Singer's longheld views on the morality of killing newborn babies [this particular quotation comes from 1980; Dr Singer has reiterated it many times since]:
This deals with the central point to which Hart objects. Two of his comments on the application of my views can be replied to more briefly. First, he is broadly correct when he says that in my view the secret killing of a normal happy infant by parents unwilling to be burdened with its upbringing would be no greater a moral wrong than that done by parents who abstain from conceiving a child for the same reasons. I say "broadly" because one should also take into account the fact that a normal infant can be given up for adoption. Hence there is a better option available to the parents of the infant, one which is not available to the parents who refrain from conceiving, unless the woman is willing to go through pregnancy and labor in order to give the child up for adoption. That requires a moral sacrifice which it is difficult to blame a woman for refusing to make. No such sacrifice is required of the parents who are imagined to be contemplating killing their infant.
Even with this caveat, my view will appear shocking to most readers, as it apparently does to Hart. But is it wrong? I still have not seen a good reason for differentiating morally between the two cases (other than "side-effects" like the factor just mentioned) and in the absence of a good reason for taking a different view, I persist in my belief that the morality of the two acts is not intrinsically different.
One might be forgiven for suggesting that a philosopher who does not find a moral difference between contraception and infanticide is not the best person to be drawing up the principles by which government should ration life-saving medical care.