A motion was proposed at the UK GA in defence of the Enlightenment. The author of the motion was sitting in front of me, and said that he just wanted to start a conversation about it. What a good idea, I said. So here goes.
The Enlightenment was a complex phenomenon with many strands. One of those strands was the origin of the Pagan revival. Another was the rise of rational religion in the form of Unitarianism, deism and humanism. A further strand was the rise of rationalism, which at the time was in opposition to the empiricism of Locke and others. The rationalists held that reason was a priori, God-given; the empiricists held that we are born with a blank slate (tabula rasa) and acquire reasoning skills by experience. It was only in the early 20th century that a synthesis of rationalism and empiricism was finally achieved. Another strand of the Enlightenment was the concept of the sublime - the experience of awe when confronted by natural phenomena such as mountains, waterfalls and wilderness. This represented a considerable shift in attitudes to nature, and it was out of this that Romanticism emerged. A further aspect of the Enlightenment was the rise of feminism, with the writings of Mary Wollstonecraft and others. There had been previous feminist writings, but Wollstonecraft represents the beginnings of a movement as opposed to a few isolated individuals. Remember also that evolution by natural selection had not yet been discovered; hardly anyone was aware of the great age of the Earth; science was still called natural philosophy; Oxford and Cambridge were Anglican-only universities and generally not very science-focussed; if you wanted to study science, the best place to go was a Dissenting Academy, like Joseph Priestley.
So the Enlightenment was a multi-faceted phenomenon, a mixture of sometimes complementary and sometimes contradictory discourses. It was an intellectual ferment, an explosion of interest in natural phenomena, history, and literature - an awakening.
The legacy of the Enlightenment is therefore also a mixed blessing. Pure rationalism has given rise to reductionism, logical positivism, behaviourism and other scientific dead-ends; but the idea that we should subject all impulses and beliefs to reason before acting on them seems to me an excellent idea. Empiricism - the primacy of experience and experiment - is also a good principle to work by. Always asking, "Yes but does it work? What are the consequences?" is a good test for most situations. And utilitarianism (another Enlightenment idea) is also useful if not carried to extremes. Seeking the greatest happiness of the greatest possible number of people is good, as long as the rights of the remaining few are not trampled.
Where the legacy of the Enlightenment has failed us is when we assume that science does not need to be tempered with other approaches. The worst excesses of industry, pollution, eugenics, behaviourist psychology and other extreme science should have been tempered with compassion and humanity.