You defend yourself against an attack by using throws and locks, like jujutsu, from which Aikido evolved. I have never studied Aikido, but from my limited exposure to it I believe that the Aikido practitioner thinks of his or her art as purely defensive. By that I mean that they are going to react to an opponent’s aggression, but in a way that is not designed to seriously hurt them. However, from what I have observed of Aikido I think a good practitioner can indeed hurt someone with the appropriate technique.
Steven Seagal:
Seagal moved to Japan at some point between 1971 and 1973. By 1974, he had returned to California. That year he met Miyako Fujitani, a second-degree black belt and daughter of an Osaka aikido master who had come to Los Angeles to teach aikido. When Miyako returned to Osaka, Seagal went with her. In 1975 they married and had a son, Kentaro, and a daughter, Ayako. He taught at the school owned by Miyako’s family. As of 1990, Miyako and her brother still taught there, and her mother was the chairwoman. Seagal returned to Taos, New Mexico, with his student (and later film stuntman) Craig Dunn, where they opened a dojo, although Seagal spent much of his time pursuing other ventures. After another period in Japan, Seagal returned to the U.S. in 1983 with senior student Haruo Matsuoka.