Aikido is the physical embodiment of philosophy.
Practicing the physical motions of it literally reprograms the nervous system and brain into the system of philosophy. Working on your ethics and intent are all part of the practice as well, of course. But in it's very design Aikido is re-imprinting the nervous system in a new way to interact with the universe around it.
I have often likened Aiki/Judo and even calligraphy practice as a system of biofeed back. When you become stressed you, or at least an observant partner can instantly pick this up - just from a simple touch. In calligraphy the brush acts as a seismographic needle putting your emotional content into the lines.
In order to do these arts correctly we must achieve a particular state of mind. If anger, frustration and ego begin to cloud the mind, immediately it is reflected in the technique we are trying to employ. Techniques fail to work, but principles and philosophy become violated.
Because of the strong sense of biofeeed back we get in practice, I feel this is one of the huge reasons the simple practice of Aikido physically conditions a philosophy into us. That is how a simple exercise can become a DO - spiritual path.
To practice a thing of beauty, like Aikido, is to become it. This calligraphy piece captures what I am trying to express.
To practice blending and softness arts is a practice of philosophy.