People are not likely to lie on the Internet about the atomic number of Rubidium, but they will lie about history.
The Science Guy
In philosophy, or religion, or ethics, or politics, two and two might make five, but when one was designing a gun or an aeroplane they had to make four.
When writing about historical characters I try to be as accurate as possible, and in particular not to misrepresent the view they held. With a real historical figure you have to be fair, and this is not an obligation you have in dealing with your own creations, so it is quite different.
In writing, fidelity to fact leads eventually to the poetry of truth.
The novelist has a responsibility to adhere to the facts as closely as possible, and if they are inconvenient, that's where the art comes in. You must work with intractable facts and find the dramatic shape inside them.
I have a rule: I will not alter the basic history of a real-life character to suit our fictional needs in a big way.
Historians ought to be precise, faithful, and unprejudiced; and neither interest nor fear, hatred nor affection, should make them swerve from the way of truth.