Reading: The Limits of Human Knowledge – Top 25 Kant Quotes

The Limits of Human Knowledge – Top 25 Kant Quotes

1. "I had to deny knowledge in order to make room for faith."

Kant sets boundaries for theoretical reason, asserting that while human knowledge has limits, this limitation opens up space for moral faith and practical reason.
(Critique of Pure Reason, Bxxx)

2. "Human reason has the peculiar fate in one species of its knowledge: that it is burdened with questions which it cannot dismiss, because they are posed by the nature of reason itself, but which it also cannot answer, because they transcend human reason."

Kant acknowledges that human reason naturally seeks answers to metaphysical questions, but it is limited in its ability to provide definitive answers to these questions.
(Critique of Pure Reason, A vii)

3. "The greatest and perhaps the sole use of all philosophy of pure reason is, after all, merely negative, since it serves not as an organon for the enlargement of knowledge, but as a discipline for its delimitation."

Kant emphasizes that the primary function of metaphysical inquiry is to clarify the boundaries of human knowledge, not to expand it beyond those boundaries.
(Critique of Pure Reason, Bxxv)

4. "We can have cognition of no object as a thing in itself, but only as an object of sensible intuition."

Kant explains that human cognition is limited to phenomena (things as they appear to us) and cannot grasp noumena (things as they are in themselves).
(Critique of Pure Reason, A30/B45)

5. "Appearances are not things in themselves but rather the mere play of our representations, which in turn are subject to the rules imposed by the understanding."

Kant argues that what we perceive are appearances, shaped by the mind’s cognitive faculties, and not the things as they are independently of our perception.
(Critique of Pure Reason, A369)

6. "The concepts of the understanding are not drawn from experience but are conditions under which experience is possible in the first place."

Kant asserts that certain a priori categories, such as causality and substance, are not derived from experience but are necessary for the possibility of having any experience at all.
(Critique of Pure Reason, B166)

7. "What is to be proved is that we can have cognition of no object as a thing in itself, but only as an object of sensible intuition."

Kant again highlights that our knowledge is limited to how things appear to us through our sensory faculties, not to the objects as they exist independently.
(Critique of Pure Reason, A30/B45)

8. "The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise."

Kant emphasizes that both sensory intuition and rational thought are necessary for knowledge, but both have limits when considered in isolation.
(Critique of Pure Reason, A51/B75)

9. "Reason itself does not take its principles from experience, it prescribes them to experience."

Kant clarifies that human reason contributes necessary structures to our experience of the world, but this means we can only know the world as it appears, not as it is.
(Critique of Pure Reason, A795/B823)

10. "Time and space are not determinations of things in themselves, but only forms of our sensible intuition."

Kant asserts that time and space are mental frameworks that organize sensory data, but they do not exist independently of human perception.
(Critique of Pure Reason, A26/B42)

11. "All cognition is limited to appearances, and we do not know things in themselves."

Kant again emphasizes the limits of human knowledge, arguing that we can only know phenomena (appearances) and not noumena (things in themselves).
(Critique of Pure Reason, A30/B45)

12. "All objects of possible experience are subject to the categories of understanding, but things in themselves are beyond the reach of our categories."

Kant distinguishes between the way we experience the world through the categories of the understanding and the unknowable realm of things in themselves.
(Critique of Pure Reason, A85/B117)

13. "The limits of sensibility do not allow us to go beyond the sphere of possible experience."

Kant states that human knowledge is confined to what can be experienced through the senses, placing a firm boundary on metaphysical speculation.
(Critique of Pure Reason, A388/B416)

14. "The concept of cause is nothing but a rule according to which objects of the senses are connected in time."

Kant redefines causality as a mental category that structures our experience, not something that can be known to apply outside the realm of appearances.
(Critique of Pure Reason, A91/B123)

15. "We can never, by means of pure reason, go beyond the limits of possible experience."

Kant argues that theoretical reason cannot reach beyond the world of experience to provide knowledge of the ultimate nature of reality.
(Critique of Pure Reason, A506/B534)

16. "No concept can have any significance if it does not relate to the possibility of experience."

Kant asserts that for concepts to be meaningful, they must be connected to possible sensory experience, limiting speculative metaphysical claims.
(Critique of Pure Reason, A239/B298)

17. "Metaphysics, as a natural disposition of reason, always strives beyond the boundaries of experience."

Kant acknowledges that human reason naturally seeks to explore metaphysical questions, but he cautions that these questions lie beyond the limits of what can be known.
(Critique of Pure Reason, A796/B824)

18. "The categories of understanding are nothing but the conditions of thought in relation to experience."

Kant asserts that the categories (like causality and substance) are necessary conditions for organizing experience, but they do not apply to things beyond experience.
(Critique of Pure Reason, A94/B126)

19. "All human knowledge begins with intuitions, proceeds from thence to concepts, and ends with ideas."

Kant describes how knowledge is structured, emphasizing that while reason can generate ideas (e.g., God, freedom), these ideas do not correspond directly to any possible experience.
(Critique of Pure Reason, A698/B726)

20. "The understanding can never go beyond the limits of sensibility."

Kant places a firm limit on what the human mind can understand, asserting that reason cannot grasp things outside of the realm of sensory experience.
(Critique of Pure Reason, A388/B416)

21. "We know a priori of things only what we ourselves put into them."

Kant argues that the mind imposes structures like space, time, and causality on experience, meaning we cannot know things as they are in themselves.
(Critique of Pure Reason, Bxviii)

22. "Pure reason cannot make the leap to knowledge of the supersensible."

Kant limits the scope of reason, arguing that it cannot provide knowledge of things like God, the soul, or the ultimate nature of reality, which are beyond possible experience.
(Critique of Pure Reason, A705/B733)

23. "The limits of possible experience are at the same time the limits of all knowledge."

Kant insists that human knowledge is bound by what can be experienced, and any claims beyond that are speculative and beyond our capacity to know.
(Critique of Pure Reason, A226/B273)

24. "The understanding is limited to applying its categories to the objects of the senses, but we cannot apply them to things beyond the sensible world."

Kant explains that while we use mental categories to structure sensory experience, these categories cannot be applied to things that lie outside of possible experience.
(Critique of Pure Reason, A248/B305)

25. "Reason must not venture beyond the bounds of possible experience, and yet it inevitably does."

Kant observes that while reason is naturally inclined to explore metaphysical questions beyond experience, such inquiries are doomed to exceed the limits of knowledge.
(Critique of Pure Reason, A686/B714)