Sign (Pāli. nimitta)

Sign of a phenomenon, thing or object perceived by the human sense faculties refers to the name or concept designated or conceptualized by the ordinary worldlings (Even the religiously unenlightened linguistic experts or specialists, who had or have created  languages, are called worldlings). The sign is expressed through the usage of various languages. Sign is sometimes called mark or characteristic. The sign is used to describe or infer the self-identity, self-nature or intrinsic nature of a phenomenon, thing or object  which does not exist in the ultimate sense. Sign is illusion in the ultimate analysis.

According to Buddhism and all other esoteric religions, such as Taoism, Buddhism, Hinduism or Unpaniṣads, Islam and so forth,  all signs (marks or characteristics) are illusive and unreal like dreams, magics, mirages, echoes and so on. The conditioned phenomena or contigent beings of the multiplicity of the empirical world or cosmos are merely the shadows of the Absolute or Reality.

Signs are mere appearances and impermanent. Only the Absolute or Essence of the shadows is eternal or real. Whoever perceives signlessness perceives the Buddha or Absolute in other esoteric  religions. The eternal Absolute is not a permanent substance but an ultimate Truth. In Mahāyāna Buddhism, the Absolute is Buddha-nature which should  be interpreted as an ultimate truth of Reality. The ultimate Truth is Emptiness, Dependent Co-arising or Totality of Interdependence in Buddhist perspective. Signs are compared to the metaphor of waves and the Absolute is akin to the metaphor of Ocean. Without the ocean, the waves do not exist. When the ocean is tranquil, there arise no waves. Signs are perceived through ordinary consciousness. Signlessnes is realized through insight or wisdom. The enlightened one or the redeemed one who has returned to the Origin is called eternal Absolute or Essence perceives signlessness. He perceives only the calm ocean without the waves (signs). The Origin is called the Non-grasping of the five aggregates according to the right vision of the Theravādins. It is called the Emptiness of the five aggregates according to the right view of the Mahāyānists. The Chan Buddhists or the Nirvāna Sūtra of the Mahāyāna tradition designates the Absolute as Buddha-nature, that is,  every human being is intrinsically a Buddha .

Gotama Buddha or Śākyamuni Buddha expounds the doctrine of Non-self or Insubstantilaity (anattā in Theravāda tradition) and Emptiness (Śūnyatā in Mahāyāna tradition) with respect to  impermanence (Anicca), Suffering (dukkha) and  Non-self (anattā) with one sole objective. The objective is to awaken the worldlings to perceive the true nature of all phenomena – signlessness. Buddhist salvation or emancipation results from the intuitive perception of signlessness . Signless liberation is expounded in both Theravāda and Mahāyāna traditions.  Perceiving signlessness annihilates the illusive selfish or egoistic self. When all human desires are purified, it is called Desireless or Selfless Desire. In this way, one can also be emancipated through the door of Desireless liberation. Whoever perceives signlessless also perceives Emptiness (i.e empty of self-nature or intrinsic nature). Perceiving Emptiness leads one to the door of Emptiness liberation. These three doors of liberation is characteristized by intuitive discernment of the illusion of the multiplicity of the empirical world - the variegated forms of the phenomenal world. Liberation occurs when the ordinary  or manifestative consciousness is transformed into released or non-manifestative consciousness. The Buddha-nature or Buddha-mind is released or non-manifestative consciousness which is purified by the Perfection of Wisdom.