Examples of begging the question by assuming unproved premises:
(a) All patriotic citizens are honest at heart,
This man charged with graft is a patriotic citizen,
∴ This man charged with graft is honest at heart.
“All patriotic citizens are honest at heart,” is not an accepted truth and thus demands proof.
(b) A famous sophism of the Greek philosopher by which he proved that motion was impossible, is an excellent illustration of an assumed premise:
“If motion is possible, a body must move either in the place where it is, or in the place where it is not;
But a body cannot move in the place where it is; and of course it cannot move where it is not,
Therefore, motion is impossible.”
Referring to this, De Morgan claims “Movement is change, and so a body requires two places in order to move.” A body cannot move in the place where it is, but must be moved from place to place. The major premise being assumed, this sophism illustrates the fallacy of begging the question.