Their three sentences are as follows:

1. Socrates: Socrates is the most famous of the ancient Greek philosophers. His thoughts focus on moral philosophy and human beings. On the discussion of cognition. The famous saying that represents his thoughts is: "Knowing one's ignorance is the greatest wisdom." This sentence reflects Socrates' humble attitude towards knowledge, believing that people should realize their own ignorance, so as to constantly pursue knowledge and truth.

2. Plato: He was a disciple of Socrates. His philosophical thoughts were deeply influenced by Socrates and he developed his own theory of ideas. The famous saying that represents his thoughts is: "A truly wise person is one who can rely on the wisdom of others to avoid being deceived." This sentence emphasizes the importance of education and personal cultivation in inspiring wisdom and preventing prejudice.

3. Aristotle: He is also a disciple of Plato. His philosophical thoughts are obviously different from Plato's, and he pays more attention to empirical observation and logical analysis. The famous quote that represents his thoughts is: "The secret of happiness lies not in seeking more of what you want, but in cultivating the ability to be free from desires." This sentence points out the true source of happiness and emphasizes the role of reason in controlling desires. importance.