The Three Marks of Existence — the tilakkhana in Pali, trilakṣaṇa in Sanskrit — are the universal characteristics that the Buddha said belong to every conditioned thing. All formations are impermanent (sabbe saṅkhārā aniccā). All formations are unsatisfactory (sabbe saṅkhārā dukkhā). All phenomena are non-self (sabbe dhammā anattā). This formula recurs throughout the Pali Canon and is given its most concentrated treatment in the Dhammapada at verses 277-279, where the Buddha says: "When one sees this with wisdom, one turns away from suffering. This is the path to purification."
The slight asymmetry of the formula is deliberate and worth attending to. The first two marks apply to saṅkhārā — formations, conditioned things, the constructed world. The third applies to dhammā — all phenomena, including the unconditioned. Impermanence and suffering belong to the made; non-self belongs to everything, including nibbana itself.
Anicca is the most directly verifiable of the three. Every aggregate — body, feeling, perception, mental formation, consciousness — arises and passes away. The breath is anicca. The thought is anicca. The cell is anicca. Empires are anicca. The Buddha's own final words at Kushinagar, recorded in the Mahāparinibbāna Sutta (DN 16), are a closing iteration of this mark: vayadhammā saṅkhārā, appamādena sampādetha — "Formations are subject to vanishing; strive on with diligence."
Dukkha as a mark of existence is wider than dukkha as the first noble truth. Here it is not only the gross suffering of pain and loss but the more refined unsatisfactoriness inherent in the very structure of conditioned experience. Anything that arises and passes cannot offer lasting satisfaction. The Salla Sutta (SN 36.6) describes how the unawakened person, struck by painful feeling, is struck by a second arrow — the mental resistance that turns sensation into suffering. Dukkha as a mark points to the structural friction the second arrow names.
Anatta is the most distinctive of the three and the hardest to receive. The Buddha's teaching that nothing whatsoever bears within itself a permanent, unchanging self is a precise negation of the Vedic tradition in which he was raised — the tradition that held ātman, the eternal self, to be identical with brahman, the absolute. In the Anatta-lakkhana Sutta (SN 22.59), the second discourse after the Setting in Motion of the Wheel, the Buddha addresses the five ascetics with a question rather than a claim. Is form permanent? No, venerable sir. And what is impermanent — is it suffering or happiness? Suffering, venerable sir. And what is suffering and subject to change — is it fitting to regard it as "this is mine, this I am, this is my self"? No, venerable sir. The five attained arahantship as the teaching landed.
This is not nihilism. The Buddha did not say there is no self; he said that whatever can be observed is not-self. The distinction is everything. In the Vacchagotta Sutta (SN 44.10), when the wanderer Vacchagotta asks directly whether the self exists, the Buddha is silent. Pressed afterwards by Ananda, he explains that either answer would mislead — to affirm a self would side with the eternalists; to deny one would side with the annihilationists. The teaching of anatta cuts between.
The three marks are not three doctrines to be believed but three lenses to be applied to direct experience. Vipassana — insight meditation, traceable to the Satipatthana Sutta (MN 10) — is the systematic seeing of the three marks in the moment-to-moment field of body and mind. When the practitioner observes a sensation arise and pass and recognises it as impermanent, unsatisfactory, and not-self, the grip of clinging loosens. This loosening is the path.
The Mahayana traditions extend the three marks in two further moves. The seal of emptiness (śūnyatā) deepens anatta into the universal lack of inherent existence; the seal of peace (nirvāṇa as śānti) makes explicit the implicit fourth: that the unconditioned is the resting place beyond all marks. But the foundation is unchanged. To see clearly is to see anicca, dukkha, anatta. The rest of the path is what follows.
