The Sages talk about the importance of truth, and proper conduct in pursuing it. But they don't talk about relativism, which is a more modern doctrine. The idea of relativism is that what is true is relative to a person's culture, or group, or even to individual experience. There is no universal or objective "truth", but only truth for my group and for yours. This is sometimes presented as a healthy doctrine that promotes tolerance. Each person is entitled to his or her own view, and no one has a right to challenge him or her on it.