Why be good to other people?

Product of evolution, or more?

Apple Siri and Google Now speak politely and kindly to us, not because they (who’s they?) truly feel so, but because their goal of existence is to assist humans, and being kind is a means to that end. We humans like to think of our compassion and kindness to others as a goal in itself, rather than a means. (Many thinkers, like Thupten Jinpa, simply postulate compassion as innate.)

Is that really so? Is compassion as innate and selfless as we think? How is our kindness to one another different from the kindness programmed into Siri?