On the Sense Organs of the Soul

[sdi]

Diogenes was fond of auditing Plato's lectures at the Academy, not so much as a student, but as a heckler. On one occasion, Plato was discoursing on the topic of the Ideas, discussing "tableness" and "cupness" and the like. Diogenes interrupted him and said, "But Plato! I can see a table and a cup, but I can't see 'tableness' and 'cupness.'"

Plato replied, "Well, while any given instance of an Idea is visible to the senses, the Idea itself is visible only to the intellect. So what you have said is natural enough, since while you have eyes, alas! you have no brain."