There is nothing outside of yourself that can ever enable you to get better, stronger, richer, quicker, or smarter. Everything is within. Everything exists. Seek nothing outside of yourself. - Miyamoto Musashi

On initial contemplation of this quote I couldn't help but feel like he's wrong. Being sick at the moment, it's hard to believe that medicine won't cure my cough. If I could internally will my cells to health I would do so - is Musashi claiming that's possible? Surely, no. However on closer inspection I believe he's referring to the idea that motivation should be self-interested. That is, if we want to get better, stronger, richer, quicker or smarter, we should do so because there exists within us a deep desire to attain those things. A truly selfish desire. He's asserting that we are (or should be) the sole deciding factor in choosing what (and how) we want to improve in our lives. Or perhaps he's claiming that the human spirit itself naturally seeks to excel, to do better, for itself. He definitely isn't promoting hermitage or cutting social integration. Which I think brings up a great insight into how we as humans interact with society. There is an aspect of our existence that calls to community to gathering for survival. These exist within group-accepted boundaries. But there is also a force in us, ever seeking expression, that pushes us to break boundaries (not laws, per se). Perhaps it is natural to want to group-up, to be together, just as it's natural to seek aloneness. However, in either case, and according to Musashi, the cause should come from within.