Is it ok to judge historical figures with modern day standards. And is it ok to say that historical figures are still human beings and not gods and its natural for them to have flaws, so they can have good aspects and bad aspects both
Historians are rarely focused on evaluating dead people and sorting them into 'good' and 'bad' columns. To take just one recent example, historians have been almost universally frustrated by the way that the media frames issues relating to the legacies of the British Empire, which is often in terms of 'progressive historians saying empire was bad vs conservative commentators saying it was good'. A system as large and long-lasting as the British Empire is complex - boiling it down to single-word adjectives is pointless in terms of analysing it. Where the real issue lies in public discourse is which stories we choose to tell ourselves - do we focus on pith helmets, brave explorers and imperial grandeur, or do we try to also tell stories about those who were ruled, exploited or fought back. Depending on whose stories we tell, empire looks very different at the end. Historians, for the most part, are concerned with telling more rather than less varied stories about the past, which is an implicit challenge to anyone who wants to think about the past in static, singular terms.
The same applies to people. Many historical figures have particular narratives associated with them - as glorious leaders or great conquerors, perhaps. Sometimes, these narratives have stood for centuries. Yet generally, when you go looking for them, alternative perspectives are not hard to find. A figure like Thomas Jefferson springs to mind - a man closely associated with the American Revolution, its early foreign policy and his eventual presidency, roles for which he might be broadly celebrated in many contexts. But it's not hard to find alternative views of Jefferson - not just from his political opponents, for example, but from the hundreds of people he enslaved over the course of his life. Historians of slavery are naturally concerned with Jefferson the owner of people rather than Jefferson the Founding Father.
It could be argued that someone like Jefferson was a product of his time and place, that we are projecting today's morality backwards to view him through the lens of someone who enslaved human beings rather than as a statesman. I would say that it's ultimately all of our personal choice as to which legacy is more important when we think of Jefferson. However from a historian's perspective, claiming someone like Jefferson as a mere product of a belief system underestimates historical actors and the extent to which people in the past were able to grapple with moral and legal dilemmas. Slavery was no monolithic institution in Jefferson's lifetime, and Jefferson held complex, changing views on the morality and continued prospects for a slave-based society. Jefferson engaged intellectually with the problem of slavery, in full knowledge of opposing arguments both practical and moral, and made his decisions to continue to be part of and help uphold that system. While it may be ahistorical to project our own personal beliefs on the past, it is not ahistorical to evaluate the motives and consequences of decisions made within complex moral and intellectual frameworks that were available to historical figures. Nor is it ahistorical to realign our perspectives as historians, and seek out different stories than the ones we are already familiar with - in fact, that's the whole point of historians in the first place.
Is it ok to judge historical figures with modern day standards.
On a personal level? Yes. Speaking for myself, I can, and most certainly will condemn every last person involved in colonial conquests, especially the Spanish and Americans, as an overall negative influence on the countries they have sullied with their presence. And I'd note that this is a very sanitised expression of my actual Views on the matter, as the original rendering wouldn't pass Rule 1.
But for the purposes of historical inquiry? It just isn't useful to do so. This is the pitfall of 'presentism', which historians try to avoid. As the following posts will demonstrate, history seeks to understand how and why people did what they did in the past, and judging people by any standard other than those that existed while they were alive isn't really useful for that purpose.
Here's some previous posts on presentism that expand more on the matter: