There could be, or not, YMMV.
I suspect that most people already know my opinions on how to investigate it...
I confess that I do not.
My feeling has always been that if a martial art purports to be built on principles, then those principles should be readily accessible in the actual physical practice of the art.
Back when I did taekwondo, my taekwondo instructor would end every class by having us recite the "tenets of taekwondo": courtesy, integrity, perseverance, self-control, and indomitable spirit. I always thought it was silly -- not that the tenets are silly things, but that it's silly to believe they are more connected to the practice of taekwondo than they are to anything else. Punching and kicking does not make us more courteous and courtesy does not make us any better at punching and kicking. The "tenets of taekwondo" are little more than an arbitrary and artificial attachment to an activity that has little to do with them.
By contrast, one of the things that appeals to me about aikido is how the principles on which it was founded are evident in the actual training. When Ueshiba talks about "the principle of non-resistance", he doesn't just mean something abstract to be meditated on; the principle of non-resistance is right there in our waza. Non-resistance is how aikido physically works.
is essential to our aikido, then (a) we should be able to explain what it is, and (b) we should be able to find it on the mat without any extracurricular investigating. I think that if we have to look outside aikido to find it, then it was never a part of aikido in the first place.