The Conceptual Scheme
Kant believed that we have an innate set of concepts – a conceptual scheme – which shape our knowledge. Bernard Williams said that without such innate concepts, the mind would be nothing more than a 'blooming, buzzing confusion', because raw, unfiltered sense experience is unintelligble and meaningless. This is because experience requires interpretation, and interpretation requires concepts: so, ultimately, in order to experience anything at all, we need to have concepts in place.
Kant's theory can be illustrated through the example of Condillac's Statue. Condillac, an empiricist, believed that if the empty mind of a statue (who, internally, was structured the same way as a human) was filled with sensations (experience), it would begin to form ideas and knowledge about itself and the external world, despite previously having an allegedly blank mind.
But Kant would disagree with Condillac's argument, claiming instead that the statue would just receive a stream of unintelligible sensations in the manner described by Williams. To form ideas, the statue at least needs to be able to recognize basic similarities between sensations – but with no prior concept of similarity, this would be impossible, and the statue's mind would be filled with a mass of random data.
It follows, then, that we must have innate concepts such as similarity, which enable us to interpret sense experience. If we can't interpret our experiences, then we can't obtain from them, or even be aware of them.
The Filing Cabinet Analogy
To further illustrate Kant's theory, an analogy involving a filing cabinet can be used. Consider an office worker who has just been given a new job: they have to file documents. The office they work in has no filing system, so thousands of documents have been placed at random in the countless drawers of the filing cabinet. If the worker is then asked to find a specific document, how can they? This is precisely the predicament…