What is "simplemindedness"

Usage examples of "simplemindedness".

But he wondered if Virgil in his simplemindedness was capable of that kind of action.

Or simply as a bubbling chuckle, an exuberance of life, perhaps even a joyous rebellion against the grimness and the simplemindedness of the hunting magic?

Which of those present did not laugh at seeing the madness of the master and the simplemindedness of the servant?

Accepting such an analysis sounds like the height of simplemindedness, and yet it is an analysis that you, and I, and both those who claim to love and those who claim to hate science fiction make, or at least accede to, every time we shop in a bookstore.