Spiritually the rules are different. That is why trying to translate spirit or Ki in a physical manner leads to lots of people coming up with physical, logical sounding explanations, way off the mark.
This is my outlook in a nutshell:
Philosophy and spirituality were at the core in the founding of Aikido. Ueshiba took a spiritually rich based personal philosophy from a lifetime of study and practice and imbued it into the physical waza.
Some participants chose to extract these philosophical and spiritual lessons from the words and teaching from the founder and make them there own (nothing wrong with that). More importantly (to me) is that they can also be learned and extracted from the physical
movements of the waza. Moreover I think this was the intention.
This for me is the key. The techniques can in this way transcend mere physical forms and teach greater lessons of a non physical nature.
Regurgitating an extracted Aikido philosophy is missing the point, for me at least. IMHO Aikido makes Buddhists better Buddhists, Christians better Christians because it reinforces the teachings inherent in those (and other) belief systems in a physical way