For Catholics, there are several non-negotiable positions, such as abortion, gay marriage, and the death penalty. And then there are unsettled issues, such as the contentious death penalty question.
On one hand, we have the clear desire of the Catholic hierarchy (most notably Pope John Paul II and Pope Benedict XVI to eliminate the death penalty and respect even the lives of murderers.
On the other hand, we have the knowledge that the Catholic Church, in medieval times, has handed individuals over to secular authorities to execution (i. e., during the Inquisition), and that saints such as Augustine and Thomas Aquinas argued in favor of the death penalty.
How is the faithful Catholic to resolve this seeming discrepancy regarding the death penalty? Very simply.
The death penalty, properly implemented, is designed to purge society of those who may be dangerous to it. But criminals are rendered less dangerous by technological advances in keeping prisoners captive.
In ancient and medieval times, societies were far more lawless than today. Dangerous individuals were more likely to escape from prison, or inspire followers to rescue them. In the modern era, however, prisons can be built to restrain all but the most desperate of criminals.
Accordingly, in situations where the public welfare is not endangered by keeping prisoners under guard, the death penalty can be eschewed.
The death penalty could and should still be brought into effect – but ONLY in very rare circumstances, namely in cases where international terrorists are present, or in the case of extremely dangerous, cunning and violent prisoners. In foreign countries which are more lawless, the death penalty might prove more common, as a deterrent to crime.
But the death penalty should not be used frivolously or for the purposes of revenge. Human life, even including the life of a murderer, is sacred, and should be protected.
The Catholic Church always errs on the side of human life – as it has done in every age. Her position concerning the death penalty throughout the ages reflects that fact. She seeks to protect the sanctity of human life, even those undeserving of it - yet she understands the danger murderers pose to civil society, and understands and approves society's right to protect itself from those criminals.