The right theory of individual freedom came from an understanding of the spontaneous evolution of civil institutions and traditions. A free society no more needed an intelligent designer than did the human species.  

The similarity of process in the development of social and biological life is brilliantly explained by one of the great defenders of freedom:

Though freedom is not a state of nature but an artifact of civilization, it did not arise from design. …

[The] development of a theory of liberty took place mainly in the eighteenth century. It began in two countries, England and Fance. The first of these knew liberty, the second did not. As a result, we have had to the present day two different traditions in the theory of liberty … the first based on an interpretation of traditions and institutions which had spontaneously grown up … the second aiming at the construction of a utopia, which has often been tried but never successfully. …

What we have called the “British tradition” was made explicit mainly by a group of Scottish moral philosophers led by David Hume, Adam Smith and Adam Ferguson, seconded by their English contemporaries Josiah Tucker, Edmund Burke, and William Paley … drawing largely on a tradition rooted in the jurisprudence of the common law. Opposed to them was the tradition of the French Enlightenment … : the Encyclopedists and Rousseau, the Physiocrats and Condorcet, are their best known representatives. …

[T]here is hardly a greater contrast imaginable between their respective conceptions of the evolution and functioning of a social order and the role played in it by liberty. …

[T]he British philosophers laid the foundations of a profound and essentially valid theory, while the [French] school was simply and completely wrong. …

Those British philosophers have given us an interpretation of of the growth of civilization that is still the indispensable foundation of the argument for liberty. They find the origin of institutions, not in contrivance or design, but in the survival of the successful. …

This demonstration … represented in some ways an even greater challenge to all design theories than even the later theory of biological evolution. For the first time it was shown that that an evident order which was not the product of a designing human intelligence need not therefore be ascribed to the design of a higher, supernatural intelligence, but that there was a third possibility – the emergence of order as the result of adaptive evolution.

-From The Constitution of Liberty by F. A. Hayek , Chapter Four: Freedom, Reason, and Tradition.

Christianity brought a thousand years of darkness down on Europe. Historically it proved to be one of the three cruelest creeds ever to afflict poor suffering mankind (the other two being Islam and Socialism in all its ruinous forms.)

The best thing that ever happened to the human race was the Enlightenment.

Joel Mokyr, professor of Economics and History at Northwestern University, has an article in City Journal which reminds us what it did for us all.

Here are parts of it:

The most hardy and irreversible effect of the Enlightenment [is]: it made us rich. It is by now a cliché to note how much better twenty-first-century people live than even the kings of three centuries back. In thousands of large and small things, material life today is immeasurably better than ever before. …  And without sounding too cocky about how progressive history is, or too triumphalist about Western culture as the crowning achievement of human development, I would like to suggest that what generated all this prosperity was the growth of certain ideas in the century after the British Glorious Revolution of 1688. …

The writers and thinkers whose work we call the Enlightenment were a motley crew of philosophers, scientists, mathematicians, physicians, and other intellectuals. They differed on many topics, but most of them agreed that improvement of the human condition was both possible and desirable. This sounds trite to us, but it is worth pointing out that in 1700, few people on this planet had much reason to believe that their lives would ever get better. For most, life was not much less short, brutish, and nasty than it had been 1,000 years earlier. The vicious religious wars that Europe had suffered for many decades had not improved things, and though there had been a few advances — the wider availability of books, for instance … — their impact on the overall quality of life remained marginal. An average Briton born in 1700 could expect to live about 35 years, spending his days doing hard physical work and his nights in a cold, crowded, vermin-ridden home.

Against this grim backdrop, Enlightenment philosophers developed a belief in the capability of what they called “useful knowledge” to advance the state of humanity. The most influential proponent of this belief was the earlier English philosopher Francis Bacon, who had emphasized that knowledge of the physical environment was the key to material progress: “We cannot command Nature except by obeying her,” he wrote in 1620 in his New Organon. The agenda of what we would call “research and development” began to expand from the researcher’s interest alone … to include the hope that one day his knowledge could be put to good use. In 1671, one of the most eminent scientists of the age, Robert Boyle, wrote that “there is scarce any considerable physical truth, which is not, as it were, teeming with profitable inventions, and may not by human skill and industry, be made the fruitful mother of divers things useful.” The idea spread to other nations. …

To bring about the progress that they envisioned—to solve pragmatic problems of industry, agriculture, medicine, and navigation—European scientists realized that they needed to accumulate a solid body of knowledge and that this required, above all, reliable communications. They churned out encyclopedias, compendiums, dictionaries, and technical volumes—the search engines of their day—in which useful knowledge was organized, cataloged, classified, and made as available as possible. One of these tomes was Diderot’s Encyclopédie, perhaps the Enlightenment document par excellence. The age of Enlightenment was also the age of the “Republic of Science,” a transnational, informal community in which European scientists relied on an epistolary network to read, critique, translate, and sometimes plagiarize one another’s ideas and work. …

The idea of material progress through the expansion of useful knowledge — what historians today call the Baconian program — slowly took root. The Royal Society, founded in London in 1660, was explicitly based on Bacon’s ideas. Its purpose, it claimed, was “to improve the knowledge of naturall things, and all useful Arts, Manufactures, Mechanick practises, Engines, and Inventions by Experiments.” But the movement experienced a veritable spurt during the eighteenth century, when private organizations were established throughout Britain to build bridges between those who knew things and those who made things. …

More and more manufacturers sought the advice of scientists and mathematicians …

The Baconian program proved unusually successful in Britain, and hence it led the world in industrial innovation. There were many reasons for this, not the least of them England’s union with Scotland in 1707. … The Universities of Edinburgh and Glasgow were the Scottish Enlightenment’s versions of Harvard and MIT: rivals up to a point, but cooperating in generating the useful knowledge underlying new technology. They employed some of the greatest minds of the time—above all, Adam Smith. The philosopher David Hume, a friend of Smith’s, was twice denied a tenured professorship on account of his heterodox [ie atheist] beliefs. In an earlier age, he might have been in trouble with the law; but in enlightened Scotland, he lived a peaceful life as a librarian and civil servant. Another Scot and friend of Smith’s, Adam Ferguson, introduced the concept of civil society. Scotland did not just produce philosophers, either; it also exported to England many of its most talented engineers and chemists, above all James Watt. …

Optimism continued to abound about the potential of useful knowledge to improve the world. In 1780, one of the greatest figures of the Enlightenment, Benjamin Franklin, wrote in a letter that “the rapid progress true Science now makes, occasions my regretting sometimes that I was born so soon. It is impossible to imagine the Height to which may be carried, in a thousand years, the Power of Man over Matter…”

The age of Enlightenment, of course, was also the age of Newton, whose discoveries made it possible to understand the movement of heavenly bodies. …

Advances in medicine proved similarly sporadic. Enlightened physicians were passionate about progress. How could they not be? Twenty out of every 100 babies perished in their first year; many young and talented women and men died prematurely of dreaded disease; adult life was often a sequence of disfiguring and debilitating sicknesses. “I see no reason to doubt that, by taking advantage of various and continual accessions as they accrue to science, the same power will be acquired over living, as it is at present exercised over some inanimate bodies,” wrote Thomas Beddoes, a learned English medic, in 1793. And there was at least one major success story in his lifetime: Edward Jenner’s discovery of the smallpox vaccine three years later. …

The Enlightenment’s contributions to long-term economic growth were not merely scientific, moreover. Many economists … have begun to see Enlightenment economic and political ideas as central to the process. … The idea that trade normally benefits both sides led to the growth of free trade after 1815 and was central to the establishment of free-trade areas in Europe and elsewhere after 1950. That understanding grew out of the Enlightenment and the thinking of such intellectual giants as Smith and Hume.

Even more important was the Enlightenment notion of freedom of expression. In our age, we think of technological change as natural and obvious; indeed, we consider its absence a source of concern. Not so in the past: inventors were seen as disrespectful, rebelling against the existing order, threatening the stability of the regime and the Church, and jeopardizing employment. In the eighteenth century, this notion slowly began to give way to tolerance, to the belief that those with odd notions should be allowed to subject them to a market test. Many novel ideas were experimented with, especially in medicine, in which new ways to fight disease were constantly being proposed and tried … Words like “heretic” to describe innovators began to disappear. …

The Enlightenment, sadly, did not end barbarism and violence. But it did end poverty in much of the world that embraced it. Once the dust settled after the upheavals and violence of the French Revolution, Europe entered a century of economic growth (known as the pax Britannica) punctuated by a few relatively short and local wars. By 1914, countries that had experienced some kind of Enlightenment had become rich and industrialized, while those that had not, or that had resisted it successfully (such as Spain and Russia), remained behind. The “club” of rich countries formed the core of the industrialized world for most of the twentieth century. …

As unlikely as it may seem, then, a fairly small community of intellectuals in a small corner of eighteenth-century Europe changed world history. Not only did they agree on the desirability of progress; they wrote a detailed program of how to implement it and then, astoundingly, carried it through. Today, we enjoy material comforts, access to information and entertainment, better health, seeing practically all our children reach adulthood (even if we elect to have fewer of them), and a reasonable expectation of many years in leisurely and economically secure retirement. … Without the Enlightenment, they would not have happened.

As David Hume did, so also Baruch Spinoza (not mentioned by Mokyr, but hugely important to his theme) unlocked the chains of religion – Christianity, Judaism, and belief in the supernatural generally – that bound mankind in superstitious dread, for those who let them.

The ideas of freedom and tolerance that inspired, and are enshrined in, the Constitution of the United States are essentially Enlightenment ideas.

Now, countering the real progress that the Enlightenment launched, socialist “progressivism” is threatening freedom, the gift of the Enlightenment out of which all others proceed.

And even more threatening is the ideology of Islam: a darkness never penetrated by the Enlightenment.

Will we let either or both succeed in bringing back the darkness?