Change my view, challenge me if you will. — obscurelaunting
It's a fairly commonplace dogma, but completely unjustified and muddled. However, it is certainly
possible to be entirely lacking in any care for others, and absolutely self-centred; that is an affliction variously labelled 'sociopath' or 'psychopath'. Much beloved of unimaginative film-makers.
The philosophical confusion stems from a confusion about causation, and about evolution. We understand that evolution proceeds not by genes being self-concerned, but by them randomly changing, and genes beneficial to survival to maturity and reproduction tending to spread in the population. And this is how we big brained apes evolved. However, big brains themselves do not and cannot follow the line of thought of evolution, because evolution is mindless to the extent of being incapable of either selfish or unselfish. Only a self can be selfish, and a self is an idea a brain has of its own functioning.
So a brain has ideas and thoughts along these lines: If I do X, Y will be the result. I want Y, therefore I will do X. And this thought, we can say, causes the brain to instruct the body to perform X. That is what is generally conceived to be the source of this universal selfishness.
The first thing to note is that Y does not cause X. it cannot cause it because it comes after it. X causes Y and Y cannot cause X. Rather it is the idea of Y that (partially) causes X. The world of the mind is the world of ideas, and it is the ideas that are causal agents. So it is perfectly possible to have all sorts of ideas that have little foundation in reality that act as behavioural causes.
But it also divorces ideas from the necessity of benefiting the person at all. For example, whenever anyone plays a game, football, cards, doctors and nurses, Super Mario, or whatever, they pretend that the goal of the game is what they want, and perform
as if it matters to them. and then they forget it is only a game. Thus one can love, because one loves the idea of love. It is a simple matter of behaving according to an idea one has in the attempt to realise it. Just like going to the store to realise the idea of a beer, or running round a field trying to kick a ball between 2 posts.