1. If friendship is for usefulness or pleasure, when this reason does not exist, the friendship will end as a matter of course. If you misjudge the person, or if the other person pretends to be deceitful, this friendship will inevitably disintegrate.

From: [Ancient Greece] Aristotle: "Nicomachean Ethics"

Introduction: Aristotle (Aristotle 384 BC - 322 BC) , ancient sage, ancient Greek, one of the great philosophers, scientists and educators in the ancient history of the world, can be called the master of Greek philosophy. He was a student of Plato and teacher of Alexander.

2. Perfect friendship exists among kind people with the same virtues, because these people have the same virtues.

From: [Ancient Greece] Aristotle: "Ethics"

3. Friendship only exists among moral people, who are similar to each other.

From: [Ancient Greece] Zeno: "The Words and Actions of Famous Philosophers"

Introduction: Zeno (about 490 BC - 425 BC), English Zeno of Elea, born in Aelia in the southern part of the Italian peninsula. Ancient Greek mathematician and philosopher, famous for Zeno's paradox.

4. Friendship is the best and most pleasant favor bestowed upon us by God. They actually think that friendship is unnecessary in life. This is simply taking the sun out of the universe!

From: [Ancient Rome] Cicero: "On Friendship"

Introduction: Marcus Tullius Cicero (January 3, 106 BC - 43 BC) December 7), a famous politician, orator, orator, jurist and philosopher in ancient Rome.

5. Friendship is nothing else, but a harmony that connects all the sacred and secular things in the world with goodwill and love.

From: [Ancient Rome] Cicero: "Monk's Robe"