Throughout the history of martial arts from geographical China, some arts more than others sought to supplement internal aspects with external aspects; some even emphasized the former at all cost to the latter; some arts opted only for external aspects, and some arts were forced to opt only for external aspects. Undoubtedly, how successful an art was in gaining and maintaining internal aspects was related to both tradition and artistic identity, but it was also likely very much related to the skills or inefficiencies of the individual practitioner. It would therefore be a sound historical hypothesis to posit that such conditions continued to influence the martial arts of Japan. Meaning, like in China, in Japan, some arts and some practitioners emphasized the internal aspects, while others did not or could not.
As internal aspects and external aspects are not the same thing, they are not trained nor cultivated in the same way. Therefore, when speaking about the training modalities of the Japanese martial arts it is unwise to first speak of them as a unified whole and then second to speak in terms of “deviation” or “anomaly” between arts without first distinguishing whether or not a given art is seeking to cultivate internal or external aspects. This is the unwise (and growing in popularity) view that sees Aikido as a deviation from those other Japanese arts wherein the senior deshi or the instructor plays the receiver role (Uke). I would suggest instead that Aikido is not a deviation from these other arts but is rather an art from a different category – an art that seeks to cultivate the internal aspects over the external aspects.
If we look at arts from China that are well known to be or that are considered to be internal arts, you do not see the instructor being the receiver of the technique. This is not for reasons of being unconscious of the so-called or imagined destructiveness of hierarchy or the patriarchy, as many modern Aikido under Americanist nihilism would suggest. Rather, this is because of the particular way in which internal aspects are cultivated - in contrast to how external aspects can be cultivated. In external aspects, it is much easier to get a deshi to move in a correct manner as the receiver of the technique (Uke) than as the doer of the technique (Nage). This is because you can more easily provide or maintain the sense or context of the technique from the receiver role. That sense or context goes on to shape the deshi’s technique in positive ways, ways not open to the junior deshi - because he/she cannot yet or does not yet comprehend the related sense or context.
For example, when I instruct law enforcement officers in defensive tactics, it is all externally based movements. There is no aim nor budget nor training time to cultivate the internal aspects at the agency level. As many law enforcement officers have little to no actual combat and/or fight experience, until they do, most do not understand the given context for this or that move. As a result, they more easily leave out this or that important detail and/or they input this or that unneeded detail. In other words, they deviate from the form. In other words, they do the form incorrectly. They do the form incorrectly because they do not understand the context: They do not understand the important details, because they do not understand the context. They do not understand the context, and so they cannot provide the context. The solution to this is to have the person that understands the context provide the context: the instructor or the senior student. Meaning, it is best when training for the external aspects to have the instructor/senior student be the receiver of the technique – the person whom provides the context for the technique. This has a much larger positive role on the performance of a deshi’s technique, externally speaking, than having the deshi be on the receiving end of the teacher’s technique. And, this is what we are seeing in those Japanese arts that have the instructor being the receiver of the technique: You are looking at external aspect training.
However, such is not the case with the internal aspects, and such is therefore not the case with Aikido training. When it comes to cultivating the internal aspects in a deshi, there are three main reasons why the deshi, not the instructor, is the receiver of the technique:
1) The acquiring of internal skills is not an intellectual process, nor one open to academic pedagogies, explanations, or linguistic descriptions. The transmission process from teacher to student occurs rather more through sense, feeling, and intuition. Toward that end, feeling the teacher’s technique, and in particular how different it feels from other deshi’s techniques and from your own, is central. It is this feeling of difference that acts as a north star to the deshi’s overall training direction. Withtout this, a deshi has no direction nor orientation – remaining lost and wandering.
2) The deshi not yet having internal aspects in their technique, within a training modality designed to cultivate those aspects, achieves nothing by having the teacher being on the receiving end. The instructor only receives an external aspect technique – meaning a technique done incorrectly. There is no progress derived from this because the deshi already knows that their technique does not feel like the teacher’s: The deshi already knows their technique is done incorrectly. Additionally, unlike with the external aspects, the internal aspects are not context dependent and therefore do not gain nor lose their sense by any context an instructor might be able to provide as the receiver of a technique. As they are not context dependent, context does not operate as a cultivator for proper execution.
3) Most importantly, the instructor having internal aspects to their technique is sending energy into the deshi/uke’s person, making the deshi’s role a yin version of internal aspect training. It is by this means that a deshi on the receiving end is being trained in the internal aspects - passively. In time, the deshi feels how their body was being organized by the teacher’s energy, and with this insight they go on to organize their body themselves in order to internalize and receive the instructor’s energy more fully and more effortlessly. This in turn becomes further developed so that the deshi can project and receive energy internally as Nage. Hence, why the best Nage, in terms of the internal aspects, was first the Uke most able to make themselves projectible (Kokyu) or adhering (Aiki).
To have the instructor be the receiver of a technique is good for developing the external aspects of the art, but it does absolutely nothing toward cultivating the internal aspects of the art.