Why Nietzsche calls himself the sun is not a metaphorical argument.

Nietzsche's claim to "the sun" is not a metaphorical argument, but a symbol or metaphor.

Nietzsche's philosophy emphasizes individual freedom, creativity and anti-traditionalism. He used the image of the "sun" to describe his thoughts, not by metaphor to show how outstanding and dazzling his thoughts were, but by giving the "sun" a specific symbolic meaning to express his thoughts.

According to Nietzsche, "the sun" symbolizes wisdom, truth and freedom. The image of "the sun" is mentioned many times in Zarathustra, which is a metaphor for his thoughts of "eternal answer" and "being yourself", and emphasizes the importance of individuals' constant pursuit of truth, wisdom and freedom.

Therefore, Nietzsche called himself "the sun" not by metaphor to show how outstanding his thoughts are, but by giving the "sun" a specific symbolic meaning to express his philosophical thoughts.