Abstract
Mechanism is a conception of the world according to which all can be explained by mechanics expressed by its fundamental concepts and principles. I’ll firstly show that, following Poincaré’s discussion on mechanical explanation, the very foundation of classical mechanics implicates that all just can’t be explained. Next, I’ll discuss the principles of mechanics as they are viewed by Poincaré, especially the principle of relativity that has a particularity in its form of “pseudo-universal”argument, as well as in its fundamental role for experiences. It will be finally revealed that, the mechanism can be used as a convention, because, by the principle of relativity, we can have only local experiments but never on the universe, and consequently, non of our experiences would never lead us to any phenomenon irreducible to mechanics. Nevertheless, it doesn’t exclude the contrary possibility: experiences can reveal that it is not to commode as it used to be, without disapproving it.