Much is made of the Catholic Church 'telling' us that the taking of human life is wrong. But do we need a church to explain this?
Suppose that the Catholic Church did not exist. Would we then be in a quandary as to what to do, or think? Would we accept whatever 'reason' was put before us and thus avoid the issue? Not so long ago, people were eliminated because they were deemed to be feeble-minded, or stood in the way of racial progress, or didn't go along with social progress, eg collectivisation, ruralisation and others. Once one has the power, finding a reason is no problem.
For the most part, we are fortunate that there is an organisation (though not without faults) and we have it to hand; that it considers the effects of taking human life on the stability of the family.