The necessary revolution in man's thinking after Immanuel Kant

world, as pure forms devoid of content, nor are they independently self-existent, but are present and active only in this preliminary cognitive operation, the one that Kant calls intuition. Since this is their particular mode of being—and we cannot deny that, because it is part of our own experience at every moment—these forms do not present themselves to us as dogmatic assumptions, and are therefore proof against sceptical criticism. Kant accordingly proposed to make these a priori forms the foundation for the sciences of mathematics and geometry, this being precisely the foundation they need.

The first part of Kant’s project, which was that of providing science with a proper foundation, impregnable against sceptical criticism, has thus been successfully completed, the sciences of mathematics and geometry having been given the firm foundation they need. These sciences, however, as he pointed out, are not by themselves adequate to yield cognition in the full and proper sense of the word, because they are purely formal. In order to give rise to cognition they have to be applied to an intuitive content which has at some time or other originated from sensory experience. Here Kant was establishing a fundamental principle of his philosophy: that human cognition is based on sensory experience, on the stimuli which give rise to the intuitional synthesis. A cognition furnishing its own content entirely from within itself would have to be a purely intellectual intuition and is imaginable only as an attribute of the Deity.

This first phase in the process of cognition—described in the section of Kant’s work headed Transcendental Aesthetics—is followed by a second phase, in which the process of cognition is brought to completion in a fully determinate experience. This phase he goes on to describe in the section of “The Critique of Pure Reason’ headed Transcendental Analytics. An intuition, he tells us there, is not in itself cognition because, simply as such, it is a ‘blind’ image, that is to say not conscious of itself. If it is to yield cognition fully completed, it has to be transformed, by undergoing a second synthesis. This consists in fitting the intuition into categories which give it content and so make it conscious of its rational meaning. These categories are such notions as number, causality, necessity and so on, which he summarised under four main heads. Kant’s name for the first of these processes is the

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