Thucydides and Plato had contrasting ways in their approach on the good life. Thucydides displays empirical thinking in his studies of human nature and behavior during the Peloponnesian War and Plato displays normative thinking in his books and dialogs in particular "The Republic"
Plato views a good life on the ideals that a person has reached happiness. When a person is in a state where they have no desires because they have all love in their life. He believed this to be the same for everyone and that exhibiting total virtue is obtainable by everyone. Plato considers virtue to be obtained when you have all love and all desires you have are gone. Having love does not mean falling in love with a person, but having a mythical understanding of the world.
Normative thinking in philosophy is thinking in terms of ideals, values, and how things should be. In "The Republic" Plato uses normative philosophies as he talks about an ideal society and the principles of justice. He focuses mainly on justice and that it is the greatest virtue and if a man is just then they are a happy person. Justice is described as each part of the soul doing its own part that is balance. Justice, in short, is a virtue, a human excellence. His next point is that acting in accordance with excellence brings happiness. Then he ties excellence to one's function. The just person is a happy person is a person who performs his function. Since these are tied together, injustice can never exceed these virtues and so justice is stronger and is the good. In The Republic, Plato refers to a man's soul of having three parts. The mind, which makes decisions, the spirit which gives courage, and the body which are the pleasures regulated by the rational mind.
The Greek Historian, Thucydides, showed his imperialistic approach when recounting the history of the Peloponnesian war between Athens and Sparta. He was a realist who had strict standards for evidence or...