Orthodoxy is the view that there exists a "transcendant moral order, to which we ought to try to conform the ways of society." Christians who look to the Bible as a guide for legislation, like Muslims who want to live under sharia, are examples of orthodoxy. They want their society to match an externally ordained moral order, so they advocate change, sometimes radical change. This can put them at odds with true conservatives, who see radical change as dangerous.
Muller next distinguished conservatism from the counter-Enlightenment. It is true that most resistance to the Enlightenment can be said to have been conservative, by definition (i.e., clerics and aristocrats were trying to conserve the old order.) But modern conservatism, Muller asserts, finds its origins within the main currents of Enlightenment thinking, when men such as David Hume and Edmund Burke tried to develop a reasoned, pragmatic and essentially utilitarian critique of the Enlightenment project.
...Muller went through a series of claims about human nature and institutions, which he said are the core beliefs of conservatism. Conservatives believe that people are inherently imperfect and prone to act badly when all constraints and accountability are removed. Our reasoning is flawed and prone to overconfidence, so it's dangerous to construct theories based on pure reason, unconstrained by intuition and historical experience.
A similar theme which I heard years ago differentiated conservative from radical, not from liberal. Liberal is rather the opposite of authoritarian. Others have juxtaposed empiricism and rationalism in a similar manner. And this theme is also characteristic of the thinking of John Gray and Isaiah Berlin, two of my favorite authors:
Gray, like his friend and mentor Isaiah Berlin, sets himself against all proponents of the grand idea – of progress, of perfectibility, of the right and only way to live. He would, one suspects, champion the bureaucrat over the ideologue any day. We love to castigate bureaucracies – look what a hate-word "Brussels" has become for our latter-day Jacobins of right and left – but consider the alternative. People who kiss their spouses goodbye in the morning, stick from nine-to-five at their humdrum desks, and come home in the evening looking forward to a nice dinner and something on the telly, are surely to be preferred to those cold-eyed demagogues, "the prophets with armies at their backs", as Isaiah Berlin has it, who conceive a burning vision of exactly how the world should work and are prepared to spill the blood of millions to ensure the imposition of their system.
You probably wouldn't be surprised to hear that opposition to that "grand idea", to the existence and desirability of one true anything, was the main inspiration for the ironic title of this here blog.