You could say it’s wrong to kill a being whenever a being is sentient or conscious. Then you would have to say it’s just as wrong to kill a chicken or mouse as it is to kill you or me. I can’t accept that idea. It may be just as wrong, but millions of chickens are killed every day. I can’t think of that as a tragedy on the same scale as millions of humans being killed.
What is different about humans? Humans are forward-looking beings, and they have hopes and desires for the future. That seems a plausible answer to the question of why it’s so tragic when humans die.
~ Peter Singer (March 8, 2009)