No one can make you feel inferior without your consent.
also attributed
No one can make me feel like a doormat without my permission.
I lately lost a preposition: It is, I thought, beneath my chair. And angrily I cried: 'Perdition! Up from out…
By doubting we come to inquiry, by inquiry we come to truth.
The explanation requiring the fewest assumptions is the most likely to be correct.
I think that this is Eleanor Roosevelt – but can’t find a source.