There were many great ācāryas, I mean to say, reformers, came. Lord Buddha also appeared in India. Then, after Lord Buddha, Śaṅkarācārya came. Then, after Śaṅkarācārya, Śrī Rāmānujācārya came. Then, after Śrī Rāmānujācārya, Madhvācārya, and then, lately, Śrī Caitanya, Lord Caitanya. He came. But you will find a link, a link, although superficially we may see that Lord Buddha is speaking something which is contradictory to Lord Śaṅkarācārya's teaching, or Rāmānujācārya is speaking something which is contradiction to Śaṅkara. No. There is no contradiction. It is the question of studying how they are paving way for ultimate spiritual realization. That requires a very, I mean to say, substantial knowledge, how they are paving the way, just step by step.
Just like Lord Buddha's teaching. Lord Buddha's teachings is... That is also detachment from matter, nirvāṇa. Nirvāṇa. But he does not speak anything about the spirit soul. Because the position in which he was speaking, that position, for the human, humanity, was not suitable for understanding what is the constitution of spirit, therefore he did not say anything about spirit. He simply preached nonviolence. So far our body is concerned, he stressed on the point that we should be nonviolent. We should not be killing animals anymore. That was his preaching. Similarly, Śaṅkara... A little more than Buddha. He said, "No, no. Matter is not all. The spirit is real thing. Matter is false." Brahma satyaṁ jagan mithyā. Now, he did not say about the activities of spiritual life. He simply gave hint that there, that matter is false. Matter is generated by spirit. Spirit is the real, principle thing. Just like Buddha did not say anything about spirit. He simply wanted that detachment of, from matter.