"His aim throughout was to produce a comprehensive worldview that accommodated both common-sense and scientific stringency. In moral philosophy, he applied his swashbuckling approach to bringing utilitarianism – the theory that goodness consists of promoting the greatest overall happiness – back to centre stage after it had been ignored for more than 50 years...he embraced its then-unpopular extreme form – act utilitarianism. Its milder version, rule utilitarianism, was "superstitious rule worship", he said, and negated precisely the deft adaptability to the actual situation that was utilitarianism's whole point."