VII: On Our Knowledge of General Principles explained

What happens

Themes in this chapter

• A Priori Knowledge

  The chapter argues that logical principles and knowledge of intrinsic value are a priori, known independently of experience though elicited by it.

• Knowledge and Certainty

  Discusses the self-evidence and indubitable certainty of logical principles, which are as certain as knowledge of sense-data.

• Truth and Falsehood

  Explores how logical principles ensure that inferences from true premises yield true conclusions, and the nature of truth in a priori knowledge.

Characters to notice

• Descartes

  Mentioned as a representative of rationalist philosophy, holding that there are innate ideas and principles known independently of experience.

• Leibniz

  Mentioned alongside Descartes as a Continental rationalist who believed in innate principles.

• Hume

  Mentioned as part of the British empiricist school, which maintained that all knowledge is derived from experience.

• Bishop Berkeley

  Mentioned as a British empiricist philosopher, part of the tradition represented by Locke, Berkeley, and Hume.

Key passages

• “We saw in the preceding chapter that the principle of induction, while necessary to the validity of all arguments based on experience, is itself not capable of being proved by experience, and yet is unhesitatingly believed by everyone, at least in all its concrete applications.”

  The principle of induction is essential for arguments from experience, but cannot be proven by experience; nonetheless, everyone accepts it in practice.

  Introduces the theme that some principles are indispensable yet empirically unprovable.

• “In all our knowledge of general principles, what actually happens is that first of all we realize some particular application of the principle, and then we realize that the particularity is irrelevant, and that there is a generality which may equally truly be affirmed.”

  We first encounter a principle through a specific instance, then recognize that the principle applies generally, beyond that instance.

  Explains how general principles are learned from particular cases.

• “The law of identity: 'Whatever is, is.' The law of contradiction: 'Nothing can both be and not be.' The law of excluded middle: 'Everything must either be or not be.'”

  Three traditional logical laws: identity (a thing is itself), contradiction (nothing can both be and not be), and excluded middle (everything either is or is not).

  Lists the classical 'Laws of Thought' as examples of self-evident logical principles.

• “All knowledge that something exists must be in part dependent on experience. When anything is known immediately, its existence is known by experience alone; when anything is proved to exist, without being known immediately, both experience and a priori principles must be required in the proof.”

  Knowledge of existence always relies on experience, either directly or indirectly through proof that combines experience with a priori principles.

  Clarifies the role of experience in existential knowledge.

• “Thus, while admitting that all knowledge is elicited and caused by experience, we shall nevertheless hold that some knowledge is a priori, in the sense that the experience which makes us think of it does not suffice to prove it, but merely so directs our attention that we see its truth without requiring any proof from experience.”

  Although experience triggers our awareness of certain truths, those truths are a priori because experience does not prove them; we see their truth directly.

  Defines a priori knowledge as independent of experiential proof, though occasioned by experience.