The purpose of Descartes Meditations is a search for truth. Descartes has set out, from a philosophical perspective, to find out what truth he can, in the world we live in. In order to do this, Descartes reasons that he must throw out all previously held knowledge and start from scratch, allowing then a closer examination of each piece of knowledge, and discovering how it can be proven to be true (or false) and then building on each discovery until he arrives at true conclusions about our world, and the verifiability of knowledge we have collected about it.
He compares his quest for knowledge metaphorically: suppose a person had a basket full of apples and wanted assurance that each apple was free from rot, would not that person remove all of the apples, and examine each apple individually? It is in this way he examines knowledge (with each piece [of knowledge] being compared to an apple, and knowledge as a whole is seen as the basket full of apples - with each part comprising a different aspect of it).
Knowledge balance sheet - accounting knowledge
English: René Descartes, the French philosopher, ...
René DescartesHowever, Descartes is a skeptic, and as such he cannot build truth from the knowledge that he doubts, and since in the first meditation he does not arrive at his first truth (something with which to construct his base of knowledge upon) he begins by setting out what he can cast into doubt. To bring to light another metaphor, that perhaps sheds more light on his approach; we turn to that of a ship at sea in desperate need for repairs. If the state of such a ship was that it was in such great need for repairs, that it would sink without them, the captain (or whoever was in charge of making such a decision) could not order that the...