But what are those claims?
No one would contradict the declaration “I like red flowers best“, because it’s something that refers to a subjective opinion. If you change the sentence to “everyone likes red flowers best” it’s legitimate to criticise it. Thus each claim on universal validity has to be justified and can be criticised by outsiders.
The statement “1+1=2” is based on mathematical postulates, which are only accepted because of the long and detailed proof given. But in everyday life there is not enough time to prove every statement with a 42 pages long essay (above all, the wood in our forests is too precious for that).
As soon as a statement is related to the community and requires a specific action or to refrain from a specific action, it is called “morality”. If we continue thinking about it, we find ourselves in the ethical sphere.
The difference between personal opinions and moral demands often is underrated. It seems as if the necessity to stand up for ones ethics feels dubious to many people.
The word “proselytise” is used on a regular basis to downgrade tries of persuasion, although it’s primary a religious action.
But when is it appropriate to proselytise, or better say persuade someone?
Imagine living in a community without women’s rights. Some people would refuse this idea. What would be the right thing to do for those? Would it be right to keep their opinion to themselves and let every man himself decide whether or not to discriminate his wife? Those people, who are really confident with their opinion that this cultural act against women is absolutely unethical, would want other people to come to the same conclusion. And who would accuse them for it? Eventually it’s the only possible way to fight injustice.
That’s something one should always have in mind when finding themselves in a situation of “proselytising”, even if the other part seems to be extremely different than his own views.
We owe it to our history of mistakes and unrighteousness to at least think about every point of view, no matter how absurd it might sound. It won’t sound as absurd as the idea, black people couldn’t be held slaves some years ago.