In randori, one must search out the opponent's weaknesses and be ready to attack with all the resources at his disposal the moment the opportunity pr… - Kanō Jigorō

In Randori we teach the pupil to act on the fundamental principles of Judo, no matter how physically inferior his opponent may seem to him, and even if by sheer strength he can easily overcome him; because if he acts contrary to principle his opponent will never be convinced of defeat, no matter what brute strength he may have used.

Jigoro Kano's Five Principles of Judo:
1. Carefully observe oneself and one's situation, carefully observe others, and carefully observe one's environment,
2. Seize the initiative in whatever you undertake,
3. Consider fully, act decisively,
4. Know when to stop,
5. Keep to the middle.

Walk a single path, becoming neither cocky with victory nor broken with defeat, without forgetting caution when all is quiet or becoming frightened when danger threatens.