When one asks a practitioner of Aikido, "What is Aikido?" one might hear, "a traditional Japanese martial art," "a way of peace," "a divine method of harnessing one's ki (bio-energy)" or "a gentle martial way." It really just depends on who you ask. Within the community of Aikido practitioners there are many different styles, which complicates things even further. Extreme philosophical differences exist between these groups and in some cases, in their methods of training. If one were to visit a Yoshinkan-affiliated dojo (training hall), one would most likely find students training intensely, throwing their partners very hard and with very similar movements. If one were to visit an Aikikai-affiliated dojo, where fluidity rather than prescribed movement is emphasized, one might see more graceful movement. In the Kokikai and Ki no Kenkyukai schools, philosophy and ideals of "ki-power" are purported. So with all these differences, just what is Aikido?
Aikido's origin can be found in the ancient art of Daito-ryu Aiki-jujutsu, said to be founded by Prince Teijun, the sixth son of the Emperor Seiwa, in the ninth century AD. The art was passed down through generations of the Minamoto family, eventually reaching Shinra Saburo Yoshimitsu, the younger brother of Yoshiie Minamoto, whose second son became known as Takeda after the area that he lived and taught in. At this time, the art was kept within the Takeda family for generations and thus was purely a samurai art during the feudal era, until Japan emerged from self-imposed isolation in the Meiji era. It was during this time that the art began to be taught to outsiders, even foreigners. It was Sokaku Takeda who first taught the art to those outside of the Takeda family. One of Takeda's most talented (and best-known) students was a man named Morihei Ueshiba. Ueshiba is the founder of modern Aikido. He was an extremely gifted martial artist and brought with him knowledge of several other martial arts. He combined his knowledge of other martial arts with the techniques of Daito-ryu, which he had learned from Takeda, to devise what would become the techniques of modern Aikido. It was within his dojo that the term "Aikido" was first used, after going by many other names, including "Aiki-Budo." It was from these beginnings that modern Aikido came to be.
Naturally, Mr. Ueshiba had many students over his lifetime, training with him at different stages of his development of Aikido. Many of his students went on to open their own dojos and their interpretation of Aikido may differ depending on when they studied with the founder. The different styles were formed by those students who started their own schools, many having developed the techniques further to suit their own needs and interpretations. In some cases, these schools represent a complete break from earlier Aikido philosophy and techniques; others are simply branches of the same teachings. Styles of Aikido include: Aikikai, headed by Morihei's grandson, Moriteru Ueshiba; Yoshinkan, founded by one of Ueshiba's most talented students, Gozo Shioda; Ki no Kenkyukai (Ki Society), founded by Koichi Tohei, one of Mr. Ueshiba's later students; Takemusu Aikido or Iwama-ryu, headed first by Morihiro Saito, and now headed by his son, Morihito; Kokikai, founded by Shuji Maruyama; and there are many other branches/styles. These styles vary in application of techniques, training methods, and philosophy. Yoshinkan Aikido, for example, was founded after World War II and is occasionally called the "hard style" because its training methods are the product of the harsh training period that Gozo Shioda spent with Morihei Ueshiba. Its training methods are generally more practical: it has about 150 basic techniques that are practiced repeatedly until mastered, enabling the student to master the remaining 3000 techniques. There are no purification rituals or ritualistic techniques, as in some of the other styles, which were developed by the founder towards the end of his life. The techniques of Aikikai Aikido may be the closest to the founder's techniques since they were the most directly transmitted, from father to son to grandson. Their teachings concentrate less on uniformity of technique among students and learning by repetition, so their technique tends to be a bit more dynamic and less mechanical. These techniques may capture the essence of what the founder taught towards the end of his life. The Ki Society's main objective is to increase their "ki-power" through breathing and other exercises. The theory is that when this ki is combined with Aikido techniques the practitioner is able to control their opponent much more easily.
Since Aikido is rooted in the martial arts used on the armored battlefields of Feudal Japan, it usually does not involve kicking. Since armor tends to be heavy, kicking would not be practical. Instead techniques usually involve joint locks or controls and/or throws. The idea is to use distance, positioning, and timing effectively in order to overcome your opponent. In this way, a smaller, weaker person could very easily overcome a much larger, stronger opponent. Many of the techniques are similar to Japanese sword techniques because of their connection with the Samurai arts. Many styles practice sword and/or jo (half-staff) techniques in their training regimens. In general, Aikido is a practical art. There are no fancy high kicks or flashy techniques, and the techniques require little strength or effort to execute. The most fundamental point in Aikido is that when performing a technique, one attacks their opponent's weakest point while maintaining one's own balance in a more favorable position in order to unbalance their opponent. In other words, the practitioner uses minimal effort in order to get the maximum effect.
The founder, towards the end of his life, espoused ideals of peace, harmony, love, cooperation, and non-aggression. This was a big change for the man who had served as an infantryman in the Russo-Japanese War and who had battled bandits in Mongolia. As a result, the techniques also changed. In Morihei's own words, "Now they were vehicles for the cultivation of life, knowledge, virtue, and good sense, not devices to throw and pin people." Generally speaking, whereas the objective of the techniques remained the same, to fell and subdue one's opponent, they were no longer executed without regard for the opponent. However, non-resistance and harmony may refer more to the effectiveness of techniques rather than to some religious ideal. Towards the end of his life, the founder stressed harmony of movement with one's opponent and non-resistance to a change of direction of movement. For example, if one's opponent pulls, it is more effective to go with them, adding one's own energy to their movement in order to control or subdue them, rather than pitting strength against strength. Similarly, if one's opponent pushes, it would be more effective to pull them in towards you. There is an expression used in Aikido, "If an opponent wants to enter, invite them in; if they want to go, send them on their way!"
All of this may be confusing to one who has never studied Aikido. Morihei Ueshiba referred to Aikido as the Art of Peace, but also worked relentlessly to improve its efficacy. One may wonder what connection martial arts have with peace, but the founder believed "The Way of the Warrior has been misunderstood as a means to kill and destroy others. The real Way of a Warrior is to prevent slaughter - it is the Art of Peace, the power of love." One may scoff at this, but it seems ever more relevant in our present world, which is filled with war and aggression.