Source can be found here. Here is the excerpt I am concerning about.
In surveying nearly two centuries of this relationship, it is wise to keep in mind an exiom of professional historians-that we should be careful not to view the past in terms of our own times, and make judgements accordignly. Certail parallels often become obvious, to be sure, but to assert what an individual president should or should not have done, by president standardds, is to violate historical context.
In the first two line, I understand the meaning but I am confused with these lines. Could anyone help me to comprehend the meaning of this context.
Certail parallels often become obvious, to be sure, but to assert what an individual president should or should not have done, by president standardds, is to violate historical context.