For the sophists, the science of eloquence became a method to earn money. In order to teach their students the art of persuasion and demonstrate their thoughts, they focused on two techniques: dialectics and rhetoric. The sophists taught their students two main techniques: the usage of sophisms and contradictions. These means distinguished the speeches of the sophists from the other speakers. Contradictions (antithesis ) were important to the Sophists because they believed that a good rhetorician should be able to defend both his own opinion and the exact opposite one. In this way, was developed the ability to find clear, convincing arguments for any thesis. For the sophists, the primary purpose was to win the dispute in order to prove their excellence in word usage. They were convinced that there was no verity, but there were different opinions, equal in importance, and the "verity" was the only one that would be more convincingly demonstrated by the rhetorician.