He cannot make a man have no soul, or make the sum of the angles of a triangle be not two right angles.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“God created the world out of nothing, contrary to the opinions of the ancients. The subject of the things that God cannot do is resumed. He cannot be a body, or change Himself; He cannot fail; He cannot be weary, or forget, or repent, or be angry or sad; He cannot make a man have no soul, or make the sum of the angles of a triangle be not two right angles. He cannot undo the past, commit sins, make another God, or make Himself not exist. Book II is mainly occupied with the soul in man. All intellectual substances are immaterial and incorruptible; angels have no bodies, but in men the soul is united to a body.” source