No matter how limited their powers of reason might have been. Still they must have understood that living like that was just murder, a capital crime - except it was slow, day-by-day murder. The government (or humanity) could not permit capital punishment for one man, but they permitted the murder of millions a little at a time. To kill one man - that is, to subtract 50 years from the sum of all human lives - that was a crime; but to subtract from the sum of all human lives 50,000,000 years - that was not a crime! No, really, isn't it funny? This problem in moral math could be solved in half a minute by any ten-year-old Number today, but they couldn't solve it. All their Kant's together couldn't solve it (because it never occurred to one of their Kant's to construct a system of scientific ethics - that is, one based on subtraction, addition, division, and multiplication).
But what then is capital punishment but the most premeditated of murders, to which no criminal's deed, however calculated it may be, can be compared? For there to be equivalence, the death penalty would have to punish a criminal who had warned his victim of the date at which he would inflict a horrible death on him and who, from that moment onward, had confined him at his mercy for months. Such a monster is not encountered in private life.