This was a horrible proposal [that the eight-year-old Albert join a friend in killing birds with a sling]....but I dared not refuse for fear he would laugh at me.
So we came to a tree which was still bare, and on which the birds were singing out gaily in the morning, without any fear of us.
Then stooping low like an Indian on the hunt, my companion placed a pebble in the leather of his sling and stretched it.
Obeying his peremptory glance I did the same, with frightful twinges of conscience, vowing firmly that I would shoot when he did.
At that very moment the church bells began to sound, mingling with the song of the birds in the sunshine.
It was the warning bell that came a half-hour before the main bell.
For me it was a voice from Heaven. I threw the sling down, scaring the birds away, so that they were safe from my companion's sling, and fled home.
And ever afterwards when the bells of Holy Week ring out amidst the leafless trees in the sunshine I remember with moving gratitude how they rang into my heart at that time the commandment: Thou shalt not kill.

- Albert Schweitzer (From 'Memoirs of Childhood and Youth')