"All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?"
About this Quote
The first question, “What can I know?”, carries the subtext of limitation. Kant is writing after the Enlightenment’s confidence and the skeptics’ demolition job; his gambit is to save knowledge by fencing it in. We can know the world as it appears to us under the mind’s organizing categories, not the thing-in-itself. That boundary isn’t a retreat; it’s a disciplined clearing of ground.
“Ought” shifts from describing the world to binding yourself to it. Kant’s moral intent is austere: ethics can’t rest on mood, tradition, or outcomes, only on a law you could rationally will for everyone. The final question, “What may I hope?”, sneaks feeling and faith back in through a side door: not as evidence about the universe, but as what practical reason is entitled to postulate (freedom, God, immortality) so that moral striving remains intelligible. Hope becomes reason’s sanctioned afterlife, not its sentimental escape hatch.
Quote Details
| Topic | Reason & Logic |
|---|---|
| Source | Unverified source: Critique of Pure Reason (Immanuel Kant, 1781)
Evidence: The whole interest of reason, speculative as well as practical, is centred in the three following questions: 1. WHAT CAN I KNOW? 2. WHAT OUGHT I TO DO? 3. WHAT MAY I HOPE? (Transcendental Doctrine of Method, Chapter II: The Canon of Pure Reason (A805/B833)). Primary source is Kant’s Critique of ... Other candidates (1) The Sense of Creation (Patrick Masterson, 2016) compilation98.8% ... All the interests of my reason , speculative as well as practical . Combine in the three following questions : 1.... |
| Cite |
Citation Formats
APA Style (7th ed.)
Kant, Immanuel. (2026, February 9). All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope? FixQuotes. https://fixquotes.com/quotes/all-the-interests-of-my-reason-speculative-as-356/
Chicago Style
Kant, Immanuel. "All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?" FixQuotes. February 9, 2026. https://fixquotes.com/quotes/all-the-interests-of-my-reason-speculative-as-356/.
MLA Style (9th ed.)
"All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?" FixQuotes, 9 Feb. 2026, https://fixquotes.com/quotes/all-the-interests-of-my-reason-speculative-as-356/. Accessed 12 Feb. 2026.






