Thucydides was the first to write a scientific history. His orations cover a large part of his unsurpassed work, which is dedicated to the Peloponnesian War. They present all the aspects of the causes that determine the actions of the opponents, while at the same time they are a lesson for each historian in terms of how to structure the speech, so that he acquires interest and analyzes in depth the historical fact. In this essay, we will first attempt to identify the main correspondences between the orations (the first with the third and the second with the fourth). On this occasion, we will refer to two more specific points. At first, we are focusing in the relationship of wisdom and cheerfulness in the speech of Archidamus II, and then in the style of Sthenelaida's speech. We will finally identify those elements that substantiate the influence of sophistry on tetralogy.