For this school of thought, "adat" plays very important role. "Adat" is the main inspiration for ethnic philosophers, as it is the intellectual legacy which belongs to a particular ethnic group. "Adat" is inherited from an ethnic's forefathers to later generations of the ethnic group. Indonesians believe that "adat" is not a human creation, but the spirits and supernatural powers ruling the community. This "adat" is very different from what Englishmen call "tradition", "custom" or "convention" today. Its meaning is not simply wider, but more particularly goes far deeper. It includes everything Englishmen call "law" nowadays; and it goes much further than law in determining the needs and the actions of individuals and the community. It ordains the ceremonies of marriage, birth and death, the times and the methods for sowing rice, building a house, praying for rain, and many other things. Economics, politics, philosophy and art all come within its sphere. Indeed, from one point of view, "adat" is simply a social expression of the community religion, in as much as it is not a human creation, and in its exercise men are still constantly watched over by the spirits and supernatural powers ruling community. Because the "adat" which regulates the entire life of the community is dominated by spirits and supernatural powers, that communal life is inevitably static and deeply conservative. Its roots lay in the obscurity of the past, when the ancestors laid down the adat once and for all, or as Minangkabau people say: "It doesn't crack with the heat or rot in the rain." In such an environment the word 'old' has a special significance, denoting something venerable, sacred, powerful and full of wisdom (Alisjahbana 1961:13-14).