Skepticism and Certainty

Where it surfaces

• Synopsis of the Six Following Meditations

  The synopsis contrasts the doubt of the First Meditation with the certainties of the cogito, God, and clear and distinct perceptions.

• Meditation I: Of the Things of Which We May Doubt

  The chapter explores radical skepticism—doubting the senses, dreams, and even mathematical truths—as a precursor to establishing certainty.

• Meditation III: Of God: That He Exists

  The meditation addresses the skeptical challenge of a deceiving God and resolves it by demonstrating that God, being perfect, cannot deceive, thus securing the certainty of clear and distinct perceptions.

• Selections from the Principles of Philosophy

  Discusses the need to doubt even evident truths until God's veracity is established, and the criterion of clear and distinct perception as the foundation of certainty.

• I

  The text contrasts the prejudices of childhood with the need for radical skepticism to achieve certain knowledge.

• II

  The passage contrasts doubt with certainty, aiming to use doubt as a tool to reach clear and certain knowledge.

• III

  The chapter distinguishes between the use of doubt for theoretical truth and the need for probable or arbitrary decisions in practical life.

• IV

  The narrator's doubt about sensory knowledge and the dream argument illustrates the skeptical challenge that Descartes seeks to overcome.

• Why we may also doubt of mathematical demonstrations

  Descartes questions the certainty of even the most secure knowledge, mathematics, by considering the possibility of constant deception.

• VII

  The chapter demonstrates how radical skepticism leads to the first certainty—the existence of the thinking self.

• VIII

  The method of doubting all corporeal existence leads to the certain knowledge of the mind's nature as thinking, establishing a foundation for certainty.

• In what sense the knowledge of other things depends upon the knowledge of God

  The mind finds certainty in demonstrations while attending to them, but doubt returns when it considers the possibility of being deceived by its creator.

• XVI

  Discusses doubt arising from habitual separation of essence and existence, and the need to overcome prejudice for certainty.

• The Guarantee of Truth Through God's Veracity

  The chapter overcomes hyperbolic doubt by establishing that clear and distinct perception, under God's guarantee, yields certainty.

• XXXI

  Descartes examines the source of error, distinguishing between the understanding and the will, and asserts that error is not caused by God but by the misuse of free will.

• That we never err unless when we judge of something which we do not sufficiently apprehend

  The chapter addresses how error occurs when judging without sufficient knowledge, emphasizing the need for certainty before assent.

• XXXIV

  The chapter addresses how judgment can occur even with obscure and confused knowledge, touching on the limits of certainty.

• XXXV

  Identifies the will's overextension beyond clear perception as the root of error, reinforcing the need for epistemic caution.

• XXXVI

  Explores the limits of human understanding and the source of error, central to Cartesian skepticism.

• XXXIX

  The chapter uses radical doubt to reveal the indubitable certainty of free will, showing that some truths survive even the most extreme skeptical scenarios.

• XLI

  Descartes argues that we should not doubt our clear consciousness of free will, even when we cannot comprehend God's infinite power.

• XLIII

  Descartes resolves skepticism by grounding certainty in clear and distinct perception, which is guaranteed by God's non-deception.

• XLIV

  Descartes critiques the false certainty derived from memory, reinforcing his skeptical approach to knowledge.

• XLV

  Descartes defines the conditions under which perception yields indubitable judgment, addressing the problem of skepticism.

• XLVI

  By showing how common judgments about pain are obscure, the chapter reinforces skeptical scrutiny of sensory knowledge.

• XLIX

  By asserting that eternal truths are self-evident and cannot be doubted when properly considered, the chapter establishes a foundation for certainty beyond skeptical doubt.

• Chapter L

  The chapter addresses how certainty of common notions is not equally accessible due to the skeptical obstacle of prejudice.

• LVIII

  Questions the objective reality of universals, reducing them to mental constructs.

• LXVI

  The chapter addresses how habitual judgments about sensations lead to uncertainty, and how restricting judgments to immediate perception yields clear knowledge.

• LXVII

  Descartes applies skeptical scrutiny to common judgments about pain, showing that our early beliefs are unreliable and must be corrected by reason.

• LXVIII

  Certainty is found in sensations as thoughts, while judgments about external objects are uncertain.

• LXIX

  The chapter reinforces the skeptical distinction between what is clearly known through intellect and what is merely sensed, establishing greater certainty for primary qualities.

• LXX

  The chapter contrasts judgments that avoid error (by acknowledging ignorance) with those that lead to error (by assuming resemblance), highlighting the skeptical stance toward sensory qualities.

• LXXI

  Descartes argues that childhood prejudices, formed from sensory impressions, are the primary source of error, undermining the certainty of knowledge derived from the senses.

• LXXII

  Highlights how preconceived opinions from childhood undermine certainty, as even clear astronomical reasoning struggles to overcome ingrained false beliefs.

• LXXIV

  The chapter highlights how verbal imprecision leads to error, reinforcing the skeptical stance that only clear and distinct perceptions can yield certainty.

• LXXV

  The precept to lay aside prejudices and withhold assent until truth is discovered reflects the skeptical method that leads to certainty through clear and distinct perception.

• LXXVI

  The chapter contrasts the absolute certainty of divine revelation with the need for critical doubt and clear perception in philosophical inquiry.

• III

  Descartes urges setting aside the prejudices of the senses, a skeptical move that clears the way for certain knowledge derived from the understanding alone.

• VII

  He challenges the assumption that only sense-perceptible bodies exist, asserting that reason can infer unperceived extended substances.

• Part IV: Of the Earth

  The chapter distinguishes moral certainty (sufficient for practical life) from absolute certainty, which is grounded in God's veracity and the proper use of reason.

• CCIV

  Acknowledges the limits of human knowledge in discerning the specific means God used to create the world.

• CCV

  Descartes introduces the concept of moral certainty as distinct from absolute certainty, acknowledging that even coherent systems may be false under God's absolute power.

• CCVI

  The chapter distinguishes moral certainty from absolute certainty, grounding the latter in God's veracity and the correct use of reason.