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“One must learn to love, one must learn to be kind, and this from childhood onwards.”
The aphorism treats loving and kind dispositions as capacities that can be practiced and cultivated rather than assumed to arise automatically.
Source note: Human, All-Too-Human, Part I, aphorism 601, “Learning to Love”; Helen Zimmern translation; this record uses the opening sentence.
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“All men by nature desire to know.”
Aristotle treats the desire for knowledge as a basic human tendency, giving curiosity a foundational place in the movement from perception toward understanding.
Source note: Metaphysics, Book I, chapter 1, W. D. Ross translation; the work opens with this claim before discussing sensation, memory, experience, art, and knowledge.
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“He who knows only his own side of the case, knows little of that.”
Understanding a position requires serious contact with competing arguments; familiarity with only one side can produce confidence without real comprehension.
Source note: On Liberty, Chapter 2; Mill argues for open discussion because opposing views expose weaknesses and sharpen understanding.
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“Reading is thinking with some one else's head instead of one's own.”
Reading supplies another mind’s thought, but Schopenhauer warns that consuming ideas should not replace the work of forming one’s own connected judgment.
Source note: Essay “On Books and Reading,” in a public-domain English collection of Schopenhauer’s essays.
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“Theories thus become instruments, not answers to enigmas, in which we can rest.”
James describes theories as tools for moving inquiry and experience forward rather than final intellectual resting places that eliminate the need for further testing or revision.
Source note: Pragmatism, Lecture II, “What Pragmatism Means”; Project Gutenberg #5116. Capitalization has been normalized from the represented all-caps sentence while the wording is otherwise preserved.
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“Pragmatism unstiffens all our theories, limbers them up and sets each one at work.”
James presents pragmatism as a method that makes theories answer to practical consequences and experience instead of allowing abstract formulations to remain rigid and self-sufficient.
Source note: Pragmatism, Lecture II, “What Pragmatism Means”; Project Gutenberg #5116. The sentence follows James’s claim that theories become instruments rather than final answers.