 Nakamura held that some of the earliest material were the "gathas" (verses) found in the Suttanipata, as well as the Sagatha-vagga of the Samyutta-Nikaya, the Itivuttakas and the Udanas.These texts use less of the doctrinal material that is developed in other texts, are more likely to promote wilderness solitude over communal living and use terminology which is similar to Jain ideas.British indologist Rupert Gethin writes that "it is extremely likely" that at least some of the suttas in the four main Nikāyas "are among the oldest surviving Buddhist texts and contain material that goes back directly to the Buddha."