I will devote myself sincerely and without reservation to the general demolition of my opinions.

Descartes makes this declaration at the outset of his project of “methodical doubt,” where he resolves to suspend or overturn beliefs that can be called into question in order to find something absolutely certain on which to rebuild knowledge. The line belongs to the opening movement of the Meditations, written in Latin (1641) and soon translated into French (1647). In the First Meditation he explains that many of his earlier opinions were acquired uncritically and that the sciences built upon them therefore lack secure foundations. The “demolition” is a deliberate, temporary clearing of the ground—an intellectual reset intended to lead to indubitable truths such as the cogito and, ultimately, a reconstructed system of knowledge.

The sentence captures Descartes’ radical methodological stance: to reach certainty, one must be willing to relinquish even deeply held convictions and treat them as provisional until they survive rigorous scrutiny. “Sincerely and without reservation” emphasizes the moral and psychological difficulty of the task—self-deception and attachment to habit are obstacles to clear reasoning. “General demolition” signals that the doubt is comprehensive rather than piecemeal: instead of correcting individual errors, Descartes proposes to challenge the foundations that support whole structures of belief. The significance is programmatic for modern philosophy, marking a turn toward foundationalism and the idea that epistemic security requires a deliberate method, not inherited authority.