 In general, it is rare for a philosopher's positions and arguments to remain the same across an entire life. This means that, in reading philosophers' works and reconstructing their arguments,  one must pay attention to the place of each work in the philosophical development of the author in question. Readers of the philosophical works of Immanuel Kant are aware of the basic distinction between his critical and precritical periods. Readers of the works of G. W. Leibniz are also aware of his philosophical development, although in his case there is less agreement on how to place his writings into a developmental scheme.