The eminent historian Paul Johnson begins his acclaimed book “Modern Times” by describing Albert Einstein’s quest at the beginning of the last century for an all-encompassing general theory of relativity and the three specific tests he determined were required to empirically validate his equations.

In a bold testament to his intellectual honesty and scientific discipline, Einstein maintained that if any of the tests did not absolutely and conclusively confirm his theory, it would be back to the drawing board. As he wrote to Arthur Eddington, secretary of the Royal Astronomical Society, in December of 1919 in reference to the third test, “If it were proved that this effect does not exist in nature, then the whole theory would have to be abandoned.”

Of course, various tests did, in fact, prove Einstein’s theory conclusively, as did every bit of empirical evidence collected since, effectively resulting in a wholesale revision of Newtonian physics.

The contrast between Einstein’s attitude and what passes for scientific rigor in some circles these days is striking. The left’s constant drumbeat about conservatism in general and the GOP specifically being “anti-science” leaves one suspecting the definition of “science” has been subject to the same terminological latitude that liberals have periodically inflicted on “marriage,” “terrorism” and “is.”

Climate change is the most potent example of this. Now. I happen to be an agnostic on the topic. There’s good data produced by respectable scientists on either side of the issue. The problem is we have no reliable way of knowing what the relevant facts are as the underlying scientific issues pertaining to climate have been undermined by political considerations. Science has been reduced to ideology.

The late Kenneth Minogue, professor emeritus of political science at the London School of Economics, wrote a seminal book in the 1980s titled “Alien Powers” in which he attempted, successfully I think, to establish a pure theory of ideology. He identified two principle elements that form an ideology: a comprehensive, programmatic system that offers an explanation for every nit and wiggle in the human condition; and the existence of an oppressor (for Marxism, the oppressor is the ruling class; for feminism, a patriarchal society; for libertarianism, the state, and so on.) For the “green” movement behind much of the climate change rhetoric, the oppressor is arguably western civilization itself, whose economic success has been built on property rights and fossil energy production.

One thing that ideology can’t bear is competition — ergo Marxism’s virulent, and often violent, repression of religion. Likewise, today’s climate change fanaticists can’t tolerate dissent, even (especially?) when that dissent comes from empirical data.

Now, the reflective properties of carbon dioxide in the atmosphere are measurable and therefore hard to refute. But there remains much we don’t know about how the atmosphere and the earth’s climate works — evidenced by the fact that much of the collected and observable data fails to conform to climate change proponents’ predictions and computer models.

But in stark contrast to scientists like Einstein, those whose intellectual curiosity compelled them to try and disprove their theories in the quest for scientific truth, many of today’s climate change ideologists — whose grants are largely contingent on providing “evidence” to support a particular economic model — simply adjust the narrative to explain how the numbers explain the theory, in other words inverting and corrupting the scientific method.

Leftist rejection of science doesn’t end with climate change. The often comical dismissal of the fields of geology and petro-physics displayed by the anti-fracking crowd is an integral part of the green ideology. Outside the environmental spectrum, radical support for abortion flies in the face of biology and every scientifically deductible definition of “life” as observed in any discipline separate of the abortion issue. And, of course, the left’s perennial confusions surrounding the “dismal science” of economics and rejection of its basic tenets is well established to the point of being definitive.

This attitude is expressed in other ways as well, such as the obnoxious habit of campus liberals to dis-invite commencement speakers from whom they might possibly learn something — such as Condoleeza Rice, the brilliant former secretary of state, and more recently, Christine Legarde, managing director of the International Monetary Fund.

What it boils down to is that it’s leftist ideology, not conservatism, that’s inherently resistant to the type of questioning leveled by scientific inquiry. Because if Einstein’s intellectual rigor were applied to liberal theories, the risk is that the truths revealed would be most inconvenient indeed.