If you do not defend yourself against an assailant, you cause harm: to yourself, your assailant, and to the public. By not resisting, you allow your assailant to harm you. You harm the assailant by not teaching him or her the error of his or her ways, which harms the public because the assailant will probably commit the same error again. The assailant's evil actions will continue because you were too selfish to risk your life or your morality to teach him or her a much needed lesson. If you resist, whether you succeed or not, you will teach the assailant that evil will not prevail. However, if you use too much violence while defending yourself, you are adding to the evil in the world through your own actions.
On the television show Star Trek-The Next Generation, there was an alien mechanical race of beings called, the Borg, who forcibly assimilated other life forms into their collective. When encountering another life form, the Borg used the motto was "resistance is futile." Resistance is not futile, but it may be painful. In a self-defense situation, you will get hurt. Remember, when two wild animals fight, one gets hurt and the other dies. It is far better to be injured than to be killed. Pain hurts, but it will go away. Death is permanent. Pain itself is not a threat to your life. If you want to survive a self-defense situation, you must learn to deal with pain. You must learn to view pain or injury as merely an inconvenience. In a life-or-death fight, ignore your pain and survive, you can lick you wounds later.
The only logical, legal, and moral use of violence is in defending yourself or another from a physical assault initiated by another person. No person is ever justified in initiating violence, even with the threat of violence, against another person or their property. The law requires you to flee from violence whenever possible. When this is not possible, then resist to your utmost.