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The Lives and Opinions of Eminent Philosophers · Chapter

Alcmaeon explained

Alcmaeon of Crotona, a pupil of Pythagoras, is noted for his medical writings and contributions to natural philosophy.

What happens

Alcmaeon of Crotona, a pupil of Pythagoras, is noted for his medical writings and contributions to natural philosophy. He is considered the first to write a treatise on natural philosophy, arguing that the moon is eternal in nature and that the soul is immortal and perpetually moving like the sun. He also held that human affairs have two sides and that only gods have certain knowledge of invisible and mortal things.

Themes in this chapter

  • Natural Philosophy and Cosmology

    Alcmaeon wrote on natural philosophy, discussing the eternal nature of the moon and the perpetual motion of the soul, akin to the sun.

  • Virtue and Self-Sufficiency

    Alcmaeon's assertion that only gods have certain knowledge while humans can only conjecture reflects a theme of epistemic humility and the limits of human understanding.

Characters to notice

  • Alcmaeon of Croton

    Main subject of the chapter; a pupil of Pythagoras, first to write on natural philosophy, argued for the immortality of the soul and the eternal nature of the moon.

  • Pythagoras

    Mentioned as the teacher of Alcmaeon.

Key passages

  • About things invisible, and things mortal, the Gods alone have a certain knowledge; but men may form conjectures.

    Only the gods possess certain knowledge of invisible and mortal matters; humans can only make conjectures.

    Alcmaeon's epistemological stance on the limits of human knowledge.

  • He used also to say that the soul was immortal, and that it was in a state of perpetual motion in the same way as the sun.

    He also claimed the soul is immortal and moves perpetually, similar to the sun.

    Alcmaeon's belief in the immortality and perpetual motion of the soul.