Two extremes 二邊（二種邊見：常、斷 / 有、無）

Two extremes (Skt. divyanta or antadvaya; Wyl. mtha 'gnyis) — eternalism and nihilism.

From a Buddhist perspective, all non-Buddhist philosophies are considered to fall into either of these two extremes. Even within Buddhism, there is an attempt by each philosophical school to avoid these extremes and to point out how other schools have to do so.

In the King of Samadhi Sutra, the Buddha said:

Existence and non-existence are extremes,

Purity and impurity are extremes as well,

Thus, having relinquished both extremes,

The wise do not dwell even in the middle.

《三摩地王經》云：「斷除有無與淨不淨二邊，亦不住中間。」

Nagarjuna wrote:

To say “it is” is a conception of permanence,

To say “it is not” is a view of nihilism,

Therefore the learned should dwell

In neither existence nor non-existence.

若取有著常，無則墮斷見，是故黠慧者，不依止有無。
~ 龍樹菩薩造、無著菩薩釋《順中論義入大般若波羅蜜經初品法門卷》

How the Four Schools Avoid the Two Extremes

• The Vaibhashikas 毗婆沙宗 avoid the extreme of eternalism since the cause has ceased at the time of the effect. They avoid the extreme of nihilism since the effect arises directly after the cause.

• The Sautrantikas 經量部 avoid the extreme of nihilism since the continua of unconditioned phenomena exist uninterruptedly. They avoid the extreme of eternalism since these phenomena are momentary.

• The Chittamatrins 唯識宗 avoid the extreme of eternalism since the imaginary/imputed nature is not truly existent. They avoid the extreme of nihilism since the dependent nature is truly existent.

• The Madhyamikas 中觀派 avoid the extreme of nihilism since all phenomena exist conventionally. They avoid the extreme of eternalism since phenomena are ultimately non-existent.

Two extremes in the Sutrayana

In the Dhammacakkappavattana Sutta 轉法輪經 in the Pali Canon, the first teaching the Buddha gave after his enlightenment, he speaks of the Middle Way, the path of practice that avoids the two extremes of sensual indulgence on the one hand, and severe asceticism on the other.