There is an objection which points out that absolute equality is not achievable. That has never stopped societies outlawing other intractable injustices such as rape, murder, apartheid or even slavery. All the great battles against injustice, in which modern societies take such pride, were considered unwinnable until, suddenly, they were won. And some of society's most mundane underpinnings depend on equally 'unachieveable' goals. Perfect verticality is a completely unachievable abstraction but it does not stop bricklayers continually checking that walls and lintels are as vertical and level as they can possibly be; we would never trust a bricklayer who did anything else [...]