Meaning of "...would be wrong if he should..."

Question

Excerpted from newrepublic.com:

The divergence between my description of historical events and the accounts of historians … is not accidental but inevitable. A historian and an artist, describing a historical epoch, have two completely different objects. As a historian would be wrong if he should try to present a historical figure in all his entirety, in all the complexity of his relations to all sides of life, so an artist would not fulfill his task by always presenting a figure in his historical significance. Kutuzov did not always ride a white horse, holding a field glass and pointing at enemies. Rastopchin did not always take torch in hand and set fire to his Voronovo house (in fact he never did it at all), and the empress Maria Feodorovna did not always stand in an ermine mantle, her hand resting on the code of law; but that is how they are pictured in the popular imagination.

I can't understand the bolded sentences, I read this as the following:

As [ a historian would be wrong if he should try to present a historical figure [ in all his entirety... to all sides of life ] ], so an artist would not fulfill his task by always presenting a figure in his historical significance.

But then its meaning is odd, it suggests a historian shouldn't present a historical figure in all his entirety, but which I think by common sense he should. Furthermore, the latter part suggests an artist would not do what a historian does, and he does this by always presenting a figure only in his historical significance, but this contradicts to what the first half suggests, it suggests historian shouldn't try to present entirely, hence should present only in historical significance, which is exactly what the latter half says an artist does!

The only possibility for it to be coherent is a historian should present a historical figure in all his entirety, but I don't see how the original context could mean it. So what exactly does these mean?

Answer 1

"Should" in this sentence can be replaced by "were to". The first part would become

a historian would be wrong if he were to try to present a historical figure in all his entirety, in all the complexity of his relations to all sides of life

What this means is that a historian should concentrate on the historical significance of the figure, rather than portray him in more detail, with trivia like his choice of clothing or his relationship with his wife.

On the other hand, the artist is both allowed (and encouraged) to make the character more interesting, larger than life, by including items that are of little historical significance and may not even be true.

Answer 2

This use of "he should try" here does not mean "he has an obligation to try".

The first two meanings of should in Merriam-Webster identify very different uses of should:

1. —used in auxiliary function to express condition <if he should leave his father, his father would die — Genesis 44:22(Revised Standard Version)>

2. —used in auxiliary function to express obligation, propriety, or expediency <'tis commanded I should do so — Shakespeare> <this is as it should be — H. L. Savage> <you should brush your teeth after each meal>

Should here is used in the first sense, not the second. It is part of a hypothetical conditional: compare the dictionary's example

[if he should leave his father], {his father would die}

with your phrase

{a historian would be wrong} [if he should try to present a historical figure...]

This should/would expresses the conditional meaning, "If this thing were to happen, then this would be the result."