Historians exercise certain qualities of character, such as

impatience
accuracy
honesty
bias

The answer is accuracy. Historians are investigators of the past or people who understand the history of people. With this field, they must have qualities such as being unbiased meaning their work should be accurate, patient, efficient reader, has a skill for logic and critical thinking and reasoning and disciplined.

this is a good question! i'll do some research and come back when i have the answer!