A DISCOVERY
Taken straight from the Black Jack wikipedia article.
In addition to his medical skills, Black Jack is a skilled fighter. While not violent by nature, he will not hesitate to use force to defend himself or others. Though preferring to fight with his fists, he will use a gun, and can use a scalpel as a throwing weapon somewhat like a shuriken.
BLACK JACK IS DR. MCNINJA. THIS IS THE ONLY EXPLANATION.
In addition to his medical skills, Black Jack is a skilled fighter. While not violent by nature, he will not hesitate to use force to defend himself or others. Though preferring to fight with his fists, he will use a gun, and can use a scalpel as a throwing weapon somewhat like a shuriken.
BLACK JACK IS DR. MCNINJA. THIS IS THE ONLY EXPLANATION.