Johann Gottlieb Fichte begins his search for the source of human knowledge with “Doubt,” the title of his first section. We humans, he argues, infer the existence of objects in the natural world from sensory impressions and from thoughts about those impressions. Everything in nature, including humans, obeys a universal law of cause and effect and is the product of an unwavering necessity. Because all we know is the product of thought, we can know only what occurs or exists in our consciousness. It is in the nature of humans to think, and we are free to choose how we think, but the way we think is determined by our nature. We cannot be other than what we are, just as objects in nature cannot be something else. From this analysis of the human intellect, Fichte arrives at two conflicting views of human existence: Humans are subject to the cause-and-effect laws of nature, yet their ability to reason will raise humans above the strict necessity that controls the natural world.
In the second section, “Knowledge,” Fichte seeks to resolve this dilemma. He does so by conducting a dialogue between “I,” representing his own, questioning self, and “Spirit,” who guides him in his quest for truth and understanding of the nature and activity of human consciousness. Through meticulous analysis of inner experience and the processes of thought, he concludes that humans synthesize mental activities, which consist of spontaneous thinking and the passive receptivity of sensation. We infer the existence and behavior of objects in the external world by combining sensation with the law of causality, but because this mental activity never extends beyond the intellect and the laws of our nature, we can never know more than ourselves. Sensation produces an image of an external object, but how we see this image is determined by the laws of our intellect, and therefore what we “see” is only ourselves “seeing.” Human consciousness is the result of this combination...
(The entire section is 805 words.)