The issue is really whether people are aware of their own biases and actively try to counter them by trying to look at events through the lens of different bias

The issue is really whether people are aware of their own biases and actively try to counter them by trying to look at events through the lens of different biases, or just run with their own biases because they're trying to promote them, generally with ulterior motives in mind. Hence George Orwell: "Those who control the present control the past, and those who control the past control the future." For example, if you ardently believe in investment capitalism as the best economic system in history, you might be reluctant to dive into the history of Wall Street's close ties to Nazi Germany in the 1930s, such as the IBM story: https://blogs.timesofisrael.com/ibm-and-the-holocaust-20-years-of-corporate-denial/ https://blogs.timesofisrael.com/ibm-and-the-holocaust-20-yea... Alternatively, if you ardently believe Marx-inspired socialism is the optimal solution, you might be reluctant to dive into the history of collectivization of agriculture in Ukraine: https://www.anneapplebaum.com/book/red-famine-stalins-war-on-ukraine/ https://www.anneapplebaum.com/book/red-famine-stalins-war-on... Historians who are merely trying to promote their own particular ideology, or to justify the past actions of their own particular nation-state, are best viewed as propaganda peddlers.