Well, for me you are really talking more about the Darwinian survival model here. Love is an output of the utility of goodwill in the survival of a society. The sacrifice of individuals is sometimes necessary for the net benefit of the group.
And in this model, personal sacrifice in favour of the group is - it seems to me - an exception to the force of individual selfishness, especially with respect to the opportunity to procreate. You see this in a colony of bees, for instance.
Altruism is a counterveiling influence against selfishness in my model of opposing forces.
The right blend of altruism and selfishness constructs the most viable society.
Now I've moved my argument into dig's turf, so I am hoping for some altruism myself.
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