Andrew Copson adds his reasoning:
I think ‘Don’t cut bits off people without their informed consent’ is a good general ethical principle. We might be flexible with this principle in the case of medically necessary procedures where children might be too young to give meaningful consent, but I think it’s a good general principle. The reasons behind it are pretty easy to grasp – respect for the dignity of a person requires respect for the integrity of their body; respect for the autonomy of a person requires that they give consent for irreversible procedures affecting their body.
Brian D. Earp quotes Dawkins:
There is no such thing as a Christian child, there is only a child of Christian parents. Whenever you hear the phrase Christian child or Muslim child or Protestant child or Catholic child, the phrase should grate like fingernails on a blackboard.
And expands with his own two cents:
A newborn baby does not hold any beliefs. A newborn baby cannot be said to believe in any God, much less the God of Judaism or Islam or Christianity. A fortiori, babies cannot endorse any customs stemming from a belief in a given supernatural entity, and certainly not a custom which requires that that same pre-verbal infant be strapped to a board and have his sex organs cut into mere days into his existence…
Those grown-up babies have had their penises irreversibly scarred in the service of beliefs they do not hold as adults. Surely there is room for the legal system of a pluralistic society to determine that these babies have a right to bodily integrity and are entitled to make decisions about their own penises when they are mentally competent to do so.
One further thought from me: I wonder what the defenders of this practice would say if, for instance, I had a vision in a dream tonight in which I felt commanded by a deity to chop off one of my child’s small toes in a sign of devotion. This becomes a matter of conscience for me. A toe is a comparably minor body part: not exactly necessary for life, but, nevertheless, something you surely shouldn’t actively remove without good reason. And if the Torah established a tradition of foreskin removal, what distinguishes its legitimacy as a practise we should tolerate from my toe-hacking vision? Time, and popularity? That makes the difference?
In which case, perhaps I should wait until I acquire some followers. Then, no doubt, there would be calls for my wishes to be tolerated in accordance with the demands of religious liberty. I’m still looking for a defence that turns this into a real debate.