At one point, JayneK suggested "double effect" as the principle to justify circuмcision.  This again rests on the presumption that no formal intent could justify it, that it's intrinsically evil.  But double effect does not apply here.  There's only one actual effect, removal of the foreskin.  I believe that she was confusing "end justifies the means" for double effect.

One of the conditions for the principle of double effect is that the action involved not be intrinsically evil.  It must be good or neutral.  So obviously when I suggested applying the principle, I was not presuming circuмcision was intrinsically evil.  (I have also explicitly mentioned that I don't think it's intrinsically evil a couple of times in this thread.)
The"end justifies the means" is a completely unacceptable idea for a Catholic and I am bit miffed that you believe I would suggest such a thing.  Actually, you are the one who sounds confused, so maybe a quick review of the principle would be useful.
The principle of double effect is applied when an action has both a good and bad effect under the following conditions:

But there are many studies which back up the claim that it dramatically reduces incidence of the sin.  "Empiricial evidence" (i.e. collected statistics can be manipulated), so one always has to investigate the possible agenda of those behind the study.  I'd prefer not to post those here, since they're rather graphic ... but several modern experts concur, based on other studies, that it dramatically reduces the sin and makes it much more difficult by eliminating the way that it's done naturally and requiring certain unnatural means.  In other words, it has to be completely deliberate.  Since the natural method is eliminated by circuмcision, it's far less likely for a boy to discover it by accident.

So I reject your conclusion that it is "not a good reason for circuмcision" simply because you saw one study (probably engineered by the anti-circuмcision crowd) which backs up your opinion.  If a Catholic were to lend credence to the other studies, which contradict yours, then they might indeed have good reason for circuмcision.

With every question, there's always a battle of studies ... depending on who's hellbent on trying to prove what.

Actually it was more than one study and they were from the pro-circuмcision side.

But the studies that support your view are just as open to being accused of having an agenda as these ones are.  You can't just assume that only the ones you don't like are agenda driven.

And even if circuмcision did reduce the incidence of this sin, it would not be a good reason for doing it.  That is like saying we should cut out our babies' tongues to prevent them from lying or cut off their hand to prevent them from stealing.

Our duty as parents is to teach the Faith to our children, teach them right from wrong, teach them to make right moral choices. We do not use any means necessary to stop them from sinning.  Following that reasoning to it logical conclusion, we would kill them immediately after baptizing them.

 Well, guess what, God commanded this ritual, and His judgement trumps yours in terms of how horrible it is.

Every time you make a comment like this you obscure the distinctions you claim you wish to make.

What God commanded was a religious ritual that would be a mortal sin if done by a Catholic.  It was also probably materially different from the circuмcision as practiced in modern times.  

The fact that God commanded a ritual thousands of years ago is completely irrelevant to any of the issues facing us now.  It does not make observance of religious circuмcision any less sinful. It does not make routine circuмcision with inadequate reasons any less horrible.  

It was useless to comment like this even once and there is certainly no reason to keep repeating it.

Even I can see this is presumption and an attempt to ease what the Church forbids in favor of a little circuмcision. Circuмcision is not to be practiced.

It's called being rational.  So instead of refuting the argument, you simply dismiss it and restate your position.  St. Thomas disagrees with you.

Routine circuмcision has always been controversial.  There have been theologians saying that there were not proportionate reason for this, while some took the other side.  This aspect is not as clear as the others.  Circuмcision as a religious observance is clearly wrong.  "Circuмcision" to treat a life-threatening illness is clearly permissible.

More likely that it did not make it to the Holy Office because it was not really an issue anywhere but America.

Correct.  And, as a result, Catholics are free to take whichever side of this issue they agree with ... without being accused of sin and even mortal sin and "loss of salvation".

It's called being rational.  So instead of refuting the argument, you simply dismiss it and restate your position.  St. Thomas disagrees with you.

No, St. Thomas doesn't disagree, as all the saints who said anything about it said not to do it. Same with Scripture and councils and the catechism. You're adding to what they said as if  to promote it. As if to promote Jєωιѕн practice turned pagan practice secretly being inflicted on Christians under the guise of false benefits that medical practitioners contest. This is how they operate in order to defy God. With your help.

No matter how many times you keep repeating this, your mere gratuitous assertion doesn't make it true.

Church has not pronounced on the question of whether the claimed medical benefits justify this procedure.  This is merely your opinion.  Stop trying to force it on the Church.  You were doing the same thing on the flat earth question, taking your opinion and one permissible view and trying to impose it on the Church, claiming that it was taught by the Church.

No matter how many times you keep repeating the opposite doesn't make it true.  As for the flat earth go to flat earth section of Cathinfo and learn that it is Scriptural, promoted by the Fathers of the Church and the globe is a pagan belief.