Constant Change – Heraclitus is best known for his cosmological teaching that all things are in constant flux or change. This is the most basic principle of the nature. He gave importance to the perception on the nature. He says, “Everything flows” just like a river. Everything is moving and nothing is remaining just as in the river. He says: “One cannot enter twice into the same river, nor can one twice touch the same mortal substance in the same state” (fragment B91). When one person steps into the river for the second time, neither the river nor the person is the same. The person would have already changed, because cells of person’s body were newly produced. The person is already in the process of becoming; and since the water in the river constantly flows, the river, where the person entered into, would have already changed within seconds; because it is the flowing water what makes the river as river. Since his entire philosophical conception is dominated by a sense of realities’ change, he is also known as “crying philosopher”.
Unity of Opposites – World is consisted of opposites. The presence of opposites makes the world as it is. The concept good and evil has its place in the order of the world. If there is no war, how can we acquire peace? The war consists of the peace. Construction is for destruction. Birth is for death. Decease demands the need of health. If there were no summer, what is the use of monsoon? The novelty of the teaching of Heraclitus is in the conception of unity in diversity, difference in unity. He considers opposites as essential to the being of the One. As a fact the One only exists in the presence of the opposites. This presence of opposites is essential to the unity of the One. The reality for Heraclitus is one; but it is multiple at the same time. This is not accidentally but essentially. It is an essential character of the reality that it should be one and many at the same time. The teaching of Heraclitus is more near to the idea of One existing in the many. Here there is Identity in Difference. He confessed that all things are One. This unity is happening only through the conflict of opposites.