Without doubt one is allowed to resist against the unjust aggressor to one's life, one's goods or one's physical integrity; sometimes, even 'til the aggressor's death... In fact, this act is aimed at preserving one's life or one's goods and to make the aggressor powerless. Thus, it is a good act, which is the right of the victim.
Thomas AquinasFor although the will cannot be inwardly moved by any creature, yet it can be moved inwardly by God.
Thomas Aquinas