Meditations on First Philosophy [1641]

Rene Descartes, in The Philosophical Writings of Descartes (John Cottingham, Robert Stoothoff, and Dugald Murdoch, eds., Cambridge University Press, 1984), vol. 2, pp. 1-62

The publication of these Meditations, in which Descartes famously strives with universal doubt in order to establish what can be known with certainty,  sparked a famous quarrel between Descartes and Hobbes.