Why is it so important that one have a firm and grounded understanding of the nature of reality, even down to minutiae irrelevant to daily life?

I posit an example:

Albert Einstein’s theories of relativity revolutionized physics, and their most immediate and notable application outside of labs was in the United States’ production of the atomic bomb, which did not win the war in itself but certainly organized the post-war order. But before all that, Albert Einstein was a Jew. So the Nazi Party and its military research arms were ideologically obligated to reject his work—to acknowledge it would be to betray one of the foundational facts of the Party and the state’s justification to sovereignty: ‘the Jew cannot innovate, they can only steal.’ So, Germany never developed atomic weapons.

Germany was a center of complex industry! Its manufactories and engineers were the envy of the world! They most likely could have built the bomb, if they tried, and thus sparked a rather different cold war, a chance to reorganize their foundering economy and reestablish their former military strength, to propagandize to various nations that weren’t terribly opposed to their ideals but just found their warring distasteful. But in order to have done so, they would have had to change their view of the world. They would no longer be Nazis, they would become a more moderate apartheid nationalism. So they never did. The Nazis were very simply incorrect about the facts of the matter, Jews can and do innovate. And this incorrectness may well have cost them the war.

From a lens of simple pragmatism, if you are seeking to avoid mistakes in the project of improving the world to your own ends, you must have a model of reality that is true.

I did not say something like ‘perhaps this was a good thing,’ because it’s not like this was a specific choice they made—it was an inherent flaw, foundational to their model of reality. The Nazis could never have won, not as long as they were Nazis. Ideological projects which are incorrect about reality will always either fail or alter themselves to be in agreement with reality, this is just the nature of any and all attempts to effect change.

Another example:

Mao Zedong was an experienced ideologue, he was a highly skilled propagandist and theoretician and military commander. He was not nearly so skilled at statecraft, and his and his allies’ ignorance caused some very significant tragedies. The best example of which may well be the order from on high to exterminate all wild sparrows, among a few other pests, on grounds they were haltering food production by eating sown seeds in the fields. Chinese farmers and soldiers killed sparrows en masse quite effectively, the sparrow population dropped, and the insects the sparrows were actually eating when they pecked the ground exploded in population, devastating the next harvest.

Had the communist leadership stuck to their guns—the revolutionary vanguard have a unique epistemic privilege, due to their lack of false consciousness, and thus it must be that the farmers are counterrevolutionaries sabotaging their own fields—it would have collapsed the burgeoning nation. Instead, they (perhaps a bit late) utilized a system developed by Mao many years earlier, known as the mass line, in which the revolutionary vanguard is obligated to speak to and truly listen to ordinary people’s description of on-the-ground issues and the state of things in order to understand their material situation and make decisions thereon. And so they changed that policy, and while it was certainly shaky for a few years, look now only to the reality of current global politics to see that success—China is not only thriving but may well inherit the US’s status as global hegemon.

And to be clear, the sparrows aren’t divorced from ideological foundations, the two examples are actually comparable. The notion of the mass line and that peasants, rather than just industrial workers, may be valued parts of socialism was a betrayal of Leninism—the original framework of early Chinese communist movements—and it’s more or less the reason Maoism is understood to be a different thing.

Ideologies and thought-frameworks in general are tools and approximations of reality, no matter how firmly an ideology might argue its perfection.

And when your conceptualization of reality conflicts with truth, you only have two options: change, or fail.