Angela asked:

What is the meaning of Kant’s famous words, ‘Thoughts without content are empty; intuitions without conceptions blind’?

Answer by Martin Jenkins

Those words of Kant epitomise his philosophy of Critical Idealism espoused in the Critique of Pure Reason. How do we know what we know? Kant sought to answer this perennial question. If I can firstly use an analogy. Think of the sealing wax and signet ring. The mind is like a signet ring because it will impose Form upon the wax – the Forms are like Conceptions or Categories. The signet ring is applied to the hot sealing wax to give it Form and the wax gives content to it. Without the shaping of the ring/Mind, there can be no content or intuitions. Without the content [or intuitions] of the wax, the Form or Categories remain empty. Both are needed in the act of synthesis.

In the Critique, Kant argues that despite many attempts, Metaphysics had failed to prove anything substantial apart from logic and tautologies. Empiricism was subject to all kinds of shortcomings as identified by the philosopher David Hume. If all knowledge was acquired by means of experience then it could never reach the status of being indubitable, of possessing certainty, of displaying necessary connections such as cause and effect. It would remain forever contingent because known only through experience and, experience could change at any time and judgements made about it would only ever be retrospective. Whilst metaphysics displayed logical certainty, it’s content was empty; whilst empiricism had content, no logical certainty meant it was contingent.

Neither Metaphysics or Empiricism on their own were suitable vehicles to acquire knowledge and to justify the claim of knowing anything. However, Kant maintained that both were involved in understanding and these elements should be combined in Synthetic a-priori judgements. That is, the necessary, a priori elements of metaphysics be combined with the a-posteriori element of empiricism.

The necessary a-priori elements Kant terms the Categories. These are the conditions which make knowing or understanding possible. The empirical aspect appears in intuitions. In the original synthetic unity of apperception, the collection of intuitions or manifolds are simultaneously combined with the Categories to appear before consciousness. This is a Synthetic a priori judgement. Categories are termed Transcendental in that although they shape and, are the very conditions of the intuitions, they are not experientially derived from them: they are the conditions which make it possible I.e. Transcending experience. If you like, the Categories are the Form and the intuition the Content of Judgements.

For example, I see a table before me. It is made possible by the Categories of Quantity [it is one object], Quality [it possesses reality in its intensity, it is not anything else and it is limited in space and time], Relation [as it partakes of substance in which it will change over time], Modality [as it necessarily exists although it is also subject to the possibility of non-existence]. The colour, texture, weight o the table are derived from intuitions within the schema of the Categories.

So when Kant writes Categories without intuitions are empty just as intuitions without Categories are blind; he means that categories are empty without the necessary content of intuitions, and intuitions without the necessary conditioning of the Categories would not be cognisable, they would be blind as we could understand them.