"Skepticism, while logically impeccable, is psychologically impossible, and there is an element of frivolous insincerity in any philosophy which pretends to accept it. Moreover, if skepticism is to be theoretically defensible, it must reject all inferences from what is experienced; a partial skepticism... has no logical justification, since it must admit principles of inference which lead to beliefs that it rejects." Russell, Human Knowledge.
Why is skepticism psychologically impossible? I am presuming he means that one cannot go about the world being a skeptic. But this presumes that actions require knowledge (if defined in a complete sense) which is at the very least a controversial position.
One can acknowledge that justification for a belief cannot be possible without having faith in certain axioms (such as the world being real) and yet still do things based on that faith. Where is the “impossibility” here? I’d argue we do this all the time.