孟子曾以常人驟見小童落井的思想實驗來論證人人皆有惻隱之心。
I am rather unsure if I should take this argument seriously since so often I see human individuals lacking this quality as of 惻隱之心. Perhaps a proper assertion is: without this quality a human is evidently suffering some incompleteness of humanity.
One with 惻隱之心 would not feel comfortable to publicize her private wish for a terrifying war not to come to an end. Neither, one with 惻隱之心 would not repeatedly argue for his approval and appreciation for such a publicized statement just to prove that he has a good taste for literature.
One with 惻隱之心would not, in order to prove what an independent truth seeker he is, manipulate with the accuracy of the reported magnitude of death befallen南京 when all Chinese mourn their countrymen just one or two generations before.
One with 惻隱之心 would not defend the colonization by the "advanced civilization" that made the red Indians walk through the "Trail of tears" while carrying the dead along the way.
It is not that they are not humans as 孟子's thought experiment would conclude, it is just that they don't have this quality called 惻隱之心, hence, though they are indeed humans but are in demand for a completion of humanity.