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“You shall listen to all sides and filter them from yourself.”
Whitman urges the reader not to borrow even his own viewpoint wholesale: other voices can be heard, but judgment still has to be worked through personally rather than accepted second-hand.
Source note: Leaves of Grass (1855), the untitled poem later known as “Song of Myself,” in the early passage telling readers not to take things at second or third hand or look through another person’s eyes. Wikisource’s 1855 scan places the sentence on printed page 14.
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“a man may have a great mass of knowledge, but if he has not worked it up by thinking it over for himself, it has much less value than a far smaller amount which he has thoroughly pondered.”
Accumulated information is distinguished from understanding: Schopenhauer values knowledge that has been actively compared, connected and reconsidered over a larger but unprocessed store.
Source note: The Art of Literature, section “On Thinking for Oneself,” T. Bailey Saunders translation; Project Gutenberg #10714. The library analogy immediately precedes the sentence.
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“They ought to be illustrations not authorities, studies not models.”
Great predecessors can teach principles without becoming templates to copy, preserving the learner’s responsibility to develop independent judgment and expression.
Source note: The Principles of Success in Literature, chapter on Style, Project Gutenberg #10420; Lewes is warning writers against imitating Cicero, Titian or other masters.
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“We must know the truth; and we must avoid error.”
James separates two intellectual duties—seeking truth and avoiding falsehood—to show that prioritizing one over the other can produce different habits of belief and inquiry.
Source note: The Will to Believe, essay “The Will to Believe”; Project Gutenberg #26659. James immediately argues that truth-seeking and error-avoidance are distinct laws rather than two phrasings of one command.
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“Our errors are surely not such awfully solemn things.”
James resists treating every possible intellectual mistake as catastrophic, because an excessive fear of error can itself prevent inquiry, experience and the possibility of gaining truth.
Source note: The Will to Believe, essay “The Will to Believe”; Project Gutenberg #26659. James is contrasting the risk of being mistaken with the cost of refusing every uncertain intellectual venture.
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“Happy is the man who learns from the misfortunes of others.”
Other people’s failures can become instruction when we pay attention to consequences before repeating the same mistake ourselves.
Source note: Moral printed after “The Lion, the Fox, and the Ass”; the fox changes his conduct after observing the ass’s fate.