Morihei Ueshiba (1883-1969), to whom Aikido pracitioners refer as "O-Sensei," was one of the world's most celebrated martial artists. His gift was to marry effective martial techniques with a deep spirituality. A master of many martial arts, he brought out budo (the martial path) a deep philosophical element. His influence on philosophical thinkers as well as martial artists has been profound.
One of the things that caught their attention is that O-Sensei was both a compassionate and a kind teacher as well as a powerful and ferocious martial artist. It is this combination of contradictory qualities that makes O-Sensei a fascinating and inspiring person.
— Susan Perry, Remembering O-Sensei