Skimming through Google’s Material design

I like that they said,

This is material design. This spec is a living document that will be updated as we continue to develop the tenets and specifics of material design.

on https://www.google.com/design/spec/material-design/introduction.html

I believe there are no absolute answers to design and things are always changing and improving.

It just seems to be a very wise statement to have in the beginning of their documentation.