Anattā: No-self, egolessness, soullessness, impersonality, absence of identity, is the last of the 3 universal characteristics of existence ti-lakkhana. This anattā doctrine, which only is taught by a Buddha, teaches that neither within the bodily, material and mental phenomena of existence, nor outside of them, can be found anything at all, that in the ultimate sense could be regarded as a self-existing, real & same, ego-entity, identity, soul, self or independently existing substance. This is the central core doctrine of Buddhism, crucial for understanding the message & method of Buddhism. It is the only really specific Buddhist doctrine, with which the entire structure of the Buddhist teaching stands or falls. All the remaining Buddhist doctrines may, more or less, be found in other philosophic systems and religions, but the anattā doctrine has been clearly and unreservedly taught only by the Buddha, wherefore the Buddha is known as the anattā - vādi or ’Teacher of impersonality ’. Whosoever has not penetrated this universal impersonality of all existence, and does not comprehend that in reality there exists only this continually self-consuming & self-referring process of arising and passing away of bodily, material and mental phenomena, and that there is no separate ego-entity or stable and same core neither within nor outside this process, he will not be able to understand Buddhism, i.e. the teaching of the 4 Noble Truths sacca, in the right light. He will think that it is his ego, his personality, that experiences suffering, his personality that performs good and evil actions and will be reborn according to these actions, his personality that will enter into Nibbāna, his personality that walks on the 8-fold path. This is the fatal ‘personalist-view’ sakkāya-ditthi and self-deception māna ‘I Am’ that keep beings wandering in Samsāra. Thus it is said in Vis.M XVI:

Mere suffering exists, no sufferer is found;
Actions are, but no actor is ever found;
Nibbāna is, but no being exists that enters it;
The path is, but no traveler is seen.

Whosoever does not understand the origin of conditionally arisen phenomena, and does not comprehend that all the actions are conditioned by ignorance, greed and hate, he thinks that it is an ego or self that understands or does not understand, that acts or causes to act, and that comes into existence at rebirth. He believes there exists an identity ‘I’ that has the sense-contact, that feels, desires, becomes attached, continues and at rebirth again enters a new existence as the same being… Vis.M XVII, 117.

While in the case of the first two characteristics it is stated that all constructions sabbe sankhārā are impermanent and subject to suffering, the corresponding text for the third characteristic states that all states, all phenomena are no-self sabbe dhammā anattā M. 35, Dhp. 279. This is for emphasizing that the common false view of an abiding, same, constant, identical self or substance is neither applicable to any ‘construction’, whether internal or external, whether physical or mental nor to any conditioned phenomenon, nor to Nibbāna, the only Unconditioned Element asankhatā - dhātu.

The Anattā-lakkhana Sutta, the ‘Discourse on the Characteristic of No-self’, was the second discourse after Enlightenment, preached by the Buddha to his first five disciples, who after hearing it attained to perfect Nobility Arahatta.

The contemplation of no-self anattānupassanā leads to the emptiness liberation suññatā-vimokkha see. vimokkha. Herein the ability of understanding paññindriya is outstanding, and one who attains in that way the path of Stream-entry is called a Dhamma-devotee dhammānusāri see: ariya-puggala, at the next two stages of sainthood he becomes a vision-attainer ditthippatta; and at the highest stage, i.e. Nobility, he is called ‘liberated by understanding’ paññā - vimutta.

For further details, see paramattha-sacca, paticca-samuppāda, khandha, ti-lakkhana, nāma-rūpa, patisandhi

Literature: Anattā-lakkhana Sutta, Vinaya I, 13-14; se e: XXII, 59; tr. in Three Cardinal Discourses of the Buddha WHEEL 17. - Another important text on Anattā is the Discourse on the Snake Simile Alagaddūpama Sutta, M. 22; tr. in WHEEL 48/49. Other texts in path. - Further: Anattā and Nibbāna, by Nyanaponika Thera WHEEL 11; The Truth of Anattā, by Dr. G. P. Malalasekera WHEEL 94; The Three Basic Facts of Existence III: Egolessness WHEEL 202/204