# XLVII explained — Philosophical Works > Chapter companion for Philosophical Works by René Descartes. ## What happens Descartes explains that to correct the prejudices of early youth, one must examine each simple notion to distinguish what is clear from what is obscure or error-prone, since the mind was once so immersed in the body that it perceived many things clearly but knew nothing distinctly. ## Themes in this chapter ### Methodical Doubt The chapter emphasizes correcting early prejudices by examining simple notions, a key step in Descartes' method of doubt. ### Reason and Method Descartes outlines a method to distinguish clear from obscure ideas, reflecting his rationalist approach to knowledge. ## Character check-ins ### Narrator The narrator reflects on the mind's immersion in the body during early years and the need to correct prejudices. ### René Descartes Descartes is the implied author, enumerating simple notions to distinguish clear from obscure ideas. ## Key lines > in our early years, the mind was so immersed in the body, that, although it perceived many things with sufficient clearness, it yet knew nothing distinctly During childhood, the mind was so entangled with the body that it saw things clearly but without distinct understanding. _This highlights the origin of prejudices that must be corrected through methodical examination._ > I will here briefly enumerate all the simple notions of which our thoughts are composed, and distinguish in each what is clear from what is obscure, or fitted to lead into error. I will list all the basic ideas that make up our thoughts, separating those that are clear from those that are unclear or likely to cause mistakes. _Descartes announces his plan to clarify simple notions as a remedy for early prejudices._ ## Links - HTML: https://www.betterreads.online/discover/philosophical_works_se/chapters/xlvii - Book: https://www.betterreads.online/discover/philosophical_works_se - All chapters: https://www.betterreads.online/discover/philosophical_works_se/chapters