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 can’t be explained. Next, I’lldiscuss the principles of mechanics as they are viewed by Poincaré, especially the principle of relativity. I’ll show that this principle has a particular feature by its form of “pseudo-universal” argument, as well as by its fundamental role for experiences. It will be finally revealed that, mechanism can be used as a convention, because, by the principle of relativity, we can have only local experiments but these can never be extended to the universe as a whole, and consequently, none of our experiences would 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.