من يعتقد أنه قادر فهو قادر.

They can because they think they can.

They can because they think they can.

A most excellent person he is, and must be allowed a little for a little conceitedness; but he may well be so, being a man so much above others.

Sooner or later, those who win are those who think they can.

"Men often become what they believe themselves to be.If I believe I cannot do something,it makes me incapable of doing it. But when I believe I can , then I acquire the ability to do it even If I didn't have it in the beginning".

he who knows himself is intelligent.

He who knows his own incapacity, knows something, after all.

He who thinks with difficulty believes with alacrity.

I'd think, maybe he truly is something extraordinary. He's what he is, that's it. Maybe that makes him strong enough, being what he is.

-I am not sure whether he's sane.
-If there's any doubt about the matter, he is.

He who can believe himself well, will be well.

Of science and logic he chatters,
As fine and as fast as he can;
Though I am no judge of such matters,
I’m sure he’s a talented man.

He did not entirely believe himself, but he knew he had best pretend he did.