If we truly aspire to do good in this world, then we must ask three questions:

1: What is necessary?
2: What is possible?
3: What is right?

“What is necessary?” and “What is possible?” depend largely on the physical realities and so become matters primarily of science. “What is right?”, or “good?”, by definition, is a matter of morality (aka “ethics” although “morality” is better).

All of us who are not psychopaths have a deeply embedded sense of right and wrong. All small children at some stage protest, with tears in their eyes, “It’s not fair” – a very definite moral judgement. Other animals too are moralists, it now turns out: dogs don’t mind small rewards for services rendered but they sulk if another dog is given a bigger reward for bringing back the same number of rabbits. Much conversation among adults is of a moral nature. How should we treat immigrants? Should there be such a gap between rich and poor? Is it right to raise animals for food? Was Deidre Barlow right to give Ken the bum’s rush?

Yet such discussion remains mostly ad hoc. Formal exploration is largely confined to religious circles, where morality tends to be framed by particular theologies, and to law-makers, who seek to reduce moral principles to rules that everyone must follow. Humanity still lacks a coherent moral philosophy on which everyone who is not a psychopath can agree. Yet moral principle matters more than anything. It is at least arguable that any political or economic system could bring net benefit to humanity and the biosphere if only the underlying morality were sound. Even feudalism can be benign, although most modern people would agree that it is far from ideal. The only exception, it seems, is neoliberalism. Modern neoliberals insist that right and wrong can simply be determined by the market. Serious moral discussion is ruled out from the start.

But are there fundamental moral principles on which we can all agree? Yes, is the serendipitous answer. At least, the world’s religions have been the principal guardians of morality these past few thousand years and, diverse though they may seem to be, the same three moral principles emerge from the heart of all of them. They are: compassion; humility, and a sense of nature’s transcendence.

Take those ideas seriously, and everything else follows.