By degrees the old collection of hymns, or the Rig-Veda, no longer sufficed. Three other collections or service-books were therefore added, making the Four Vedas. The word Veda is from the same root as the Latin _vid-ere_, to see: the early Greek _feid-enai_, infinitive of _oida_, I know: and the English _wisdom_, or I _wit_. The Brahmans taught that the Veda was divinely inspired, and that it was literally "the _wisdom_ of God." There was, first, the Rig-Veda, or the hymns in their simplest form. Second, the Sama-Veda, made up of hymns of the Rig-Veda to be used at the Soma sacrifice. Third, the Yajur-Veda, consisting not only of Rig-Vedic hymns, but also of prose sentences, to be used at the great sacrifices; and divided into two editions, the Black and White Yajur. The fourth, or Atharva-Veda, was compiled from the least ancient hymns at the end of the Rig-Veda, very old religious spells, and later sources. Some of its spells have a similarity to the ancient German and Lithuanian charms, and appear to have come down from the most primitive times, before the Indian and European branches of the Aryan race struck out from their common home. To each of the four Vedas were attached prose works, called Brahmanas, in order to explain the sacrifices and the duties of the priests. Like the Four Vedas, the Brahmanas were held to be the very word of God. The Vedas and the Brahmanas form the revealed Scriptures of the Hindus--the _sruti_, literally "Things _heard_ from God." The Vedas supplied their divinely-inspired psalms, and the Brahmanas their divinely-inspired theology or body of doctrine. To them were afterward added the Sutras, literally "_Strings_ of pithy sentences" regarding laws and ceremonies. Still later the Upanishads were composed, treating of God and the soul; the Aranyakas, or "Tracts for the forest recluse;" and, after a very long interval, the Puranas, or "Traditions from of old." All these ranked, however, not as divinely-inspired knowledge, or things "heard from God" (_sruti_), like the Vedas and Brahmanas, but only as sacred traditions--_smriti_, literally "The things _remembered_."