I would like to ask this question:
Is it necessarily to do any further study in Buddhism if one practices Zazen? Al insights should arise naturally out of the sitting practice. To give a simple example, should one read in a book or hear in talk that all things are impermanent if that is not your own insight yet, it will merely be a concept. And when one gets this insight out of practice it is not necessary to hear that from others.
I put it very simple here, but I hope you know what I mean.