Meditations on First Philosophy

I again undertake to treat of God and the human soul, and at the same time to discuss the principles of the entire First Philosophy (...) I would advise none to read this work, unless such as are able and willing to meditate with me in earnest, to detach their minds from commerce with the senses, and likewise to deliver themselves from all prejudice. - Taken from "Meditations on First Philosophy" written by René Descartes