Although different from Indian Buddhism in form and practice, in the end Zen seems to be more authentic than many other Buddhist schools. In particular, Zen emphasizes the necessity of practice leading toward enlightenment, which is the very foundation of Buddhism. As we know, the principle of not-self is used only as a means to open the way of Buddhism - it is not a dogma. The principle of not-self is applied to both the world of living beings and the world of inanimate things. Not-self signifies absence of permanent identity. Not-self is impermanence itself. Everything is constantly changing. Therefore, nothing can be fixed in its identity. Everything is subject to not-self.
Thich Nhat Hanh, Zen Keys