A Treatise of Human Nature · Chapter
Section XIII: Of Unphilosophical Probability explained
Hume explores the nature of probability and belief, arguing that all judgments short of knowledge derive from the force and vivacity of perceptions.
What happens
Hume explores the nature of probability and belief, arguing that all judgments short of knowledge derive from the force and vivacity of perceptions. He examines how custom and general rules influence the imagination, leading to unphilosophical probabilities that can contradict judgment. He illustrates these principles with examples of open versus concealed satire, and the differing influence of direct versus oblique evidence on the passions.
Themes in this chapter
Custom and General Rules
Hume explains how general rules, formed by custom, influence the imagination and can lead to unphilosophical probabilities, sometimes contradicting judgment.
Skepticism About the External World
The chapter highlights contradictions in human reason, showing how general rules can subvert and then save philosophy, reinforcing skeptical doubts about the foundations of knowledge.
Association of Ideas
The force and vivacity of ideas, central to belief, are influenced by the association of ideas through custom and habit, as seen in the transition from cause to effect.
Characters to notice
- David Hume
Author and narrator, presenting his philosophical system on probability and belief.
- Cardinal de Retz
Referenced for observations on how the world wishes to be deceived and excuses actions more than words.
Key passages
“Thus it appears upon the whole, that every kind of opinion or judgment, which amounts not to knowledge, is derived entirely from the force and vivacity of the perception, and that these qualities constitute in the mind, what we call the belief of the existence of any object.”
In summary, all opinions that fall short of certain knowledge come from the strength and liveliness of our perceptions, and these qualities are what we call belief in an object's existence.
Hume's core thesis that belief is a matter of felt force and vivacity, not rational certainty.
“The following of general rules is a very unphilosophical species of probability; and yet it is only by following them that we can correct this, and all other unphilosophical probabilities.”
Following general rules is an irrational kind of probability, but it's the only way we can correct this and other irrational probabilities.
Hume's paradox: general rules are both the source of error and the means of correction.
“One who lashes me with concealed strokes of satire, moves not my indignation to such a degree, as if he flatly told me I was a fool and coxcomb; though I equally understand his meaning, as if he did.”
A person who insults me indirectly with subtle satire doesn't anger me as much as if they directly called me a fool, even though I understand their meaning just the same.
Illustrates how the manner of presentation affects the force of an idea and its influence on the passions.