Rene Descartes had a philosophical treatise published in 1647 called the meditations on the first philosophy (Statile et al. 2010, pp.548). His book has six different meditations that include meditation of the things called doubt, meditation of the nature of the human mind, meditation of the existence of God, meditation that concerns true and false, meditation that concerns the importance of the material things, and the meditation that concerns the differences between mind and body.
First Meditation: Doubtful Things
This mediation called skeptical doubts starts as the mediator makes a reflection on some of the beliefs during his lifetime that now he attest as falsehoods. ...