Sustainability is founded on altruism – caring for others. Auguste Comte (1798 -1857) coined the word, proposing that we should 'live for others' – vivre pour autrui – instead of living for God, or money, or self-gratification.
Living for others can be based on religion (Christianity "love your neighbor", Islam "give alms"), humanism (Do unto others ...), family loyalty ("He's my brother), as a freestanding moral virtue (It's the right thing to do) or the evolutionary imperative (alone we die).
And sustainability – the altruism of caring for all others down to through many generations – is for all practical purposes socialism: how we as societies or as a species manage our commons – the resources, risks, and challenges we share in common with others.
Over the past decade I have been alarmed by an increase in what I will call "missionary conclusions" jumped to by many so groups religious, commercial, technical, military, Left, Right, and Extraterrestrial. These conclusions – unsustainable and un-altruistic – go something like this: "We know the truth, (the whole truth and nothing but the truth) and know what to do to create the right future for everyone. Others who do not accept our truth or support our programs may – indeed should – be forced into compliance – for their own good as well as that of future generations – with whatever coercion or violence it takes."