Kant, a German classical philosopher, divided human cognitive activities into three stages.

Kant, a German classical philosopher, divided human cognitive activities into three stages, namely, sensibility, intellectuality and rationality.

In Kant's philosophical system, the perceptual stage is the direct perception and understanding of the external world through the senses, which provides information about the concrete image and superficial phenomena of things based on experience.

The intellectual stage is the stage when people use concepts and categories to process and organize perceptual knowledge. Kant believes that people can raise perceptual knowledge to the level of concept and category through intellectuality, thus forming a profound understanding and analysis of things.

The rational stage is a stage in which people integrate and promote intellectual knowledge at a higher level through reasoning and judgment. Kant believes that reason can transcend the limitations of sensibility and intellectuality, and gain a more comprehensive and in-depth understanding through higher-level thinking and reasoning.

Kant's theory has a far-reaching influence on philosophy, epistemology and other fields, and is considered as a classic of German classical philosophy.