The principle of ‘tilakkhan᷂a, or in some contexts is also called ‘theory of Three Characteristics’, is one of the exalted principle of Buddhism. The theory profoundly explains the general trait and characters of naturally extant substante and beings in this world. In some occasion it can be called ‘sāmaňňa-lakkhn᷂a’ – [sāmaňňalukṥn᷂a S.]. The word ‘ti’ [Pāli] or ‘tri’ [Sanskrit] means ‘three’ whilst ‘lakkhan᷂a’ is literally translated ‘characteristics’. Therefore, altogether, the principle is well accepted as ‘the Three Characteristics’.
Buddhist traditions, especially, from Theravādin Schools admit that Buddha demonstrates this theory intentionally referring to general characters of all beings and substances which are conditioned by or consisted from the great four elements [rūpakhan᷂dha; pat᷂havī-dhātu, āpo-dhātu, tejo-dhātu, and vāyo-dhātu] such as mountain, tree, and general materials, or from the five aggregates [paňca-khan᷂dhāni] which is believed to condition the existence of human-beings like us. Therefore, according the principle, Buddhists believe that we are bound to these three characteristics since the day we were born, or in the other expression, one might describe it in short that ‘the Three Characteristics’ are the innate traits of the five aggregates because they are bound to these three;
1. ‘aniccatā’ – Literally means ‘impermanence or transiency’. The theory profoundly explains Buddhist belief that all beings and substances are subjected to the state of impermanence, change and decadence. It is believed to be stated by the Buddha in ‘Sanggatalakkhan᷂asutta: the discourse of conditioned characteristics’ in Anggutara Nikāya that all substances emerge [upapada], subjected to alteration while existing [t᷂hitassa aňňathattā], and extinction [bhangga] at the end of the wondering circle. Furthermore, the theory which is believed to be established earlier in the time of the Buddha, is also vividly enhanced the explanation by the prominent commentator, Buddhaghosa, in around the 10th century B.C.E in his well- known scholarly work called ‘visuddhimagga: the path of purification’.
In his work, Buddhaghosa vividly explains that impermanence is bound to all beings- nothing lasts for eternity. However, because of all things seem to possess the condition of continuation [santati], therefore we tend to overlook and see it as permanent phenomena. For instance, the continuous growth of a child, if we observe that child every day and every moment of our lives, our perception automatically assumes that there is no alteration in that child. This perception is related to the way we perceive our aging condition and deterioration in which it seems unchanged at all.
2. ‘dukkhatā’ – It is iterally translated as ‘state of suffering or being oppressed’. It is also comprehensively explained by Buddhists that it is the ‘state of vulnerable and hard to persist’, and ‘state of unsustainability’. Buddhism also describes and categorizes this view vividly in many approaches. For instance; ‘tukka-tukkatā’ – suffering because of the feeling or perception of sufferings, for example we feel suffer from physical suffering like pain then leads to mental suffering like worrying and uncomfortable from our pain. ‘sangkhara-tukkhatā’ – suffering because of conditioned factors physically occur to all substances in which we hardly bear to its alteration and unsustainability such as, human-being cannot sit still forever. At a certain stage, we have to change our gesture and position to release physical pain, as well as our physical condition does not sustain in the same condition for eternity- it deteriorates and decays at the end. ‘viparināma-tukkhatā’ – suffering conditioned by change and variation. It is believed to be the suffering which occurs even within our happiness. There is actually the acceptance of ‘happiness’ in Buddhist theory. However, this ‘happiness’ state also contains ‘suffering’ inside it every moment because of fear and worry of losing that ‘happiness’ at the end.
3. ‘anattata’ – It is literally interpreted ‘soullessness; or a state of being not self’. Buddhists believe that all substances and beings are subjected or conditioned to the law of nature – nothing is subjected to our control. The meaning is categorized into two groups;  ‘the state of being not self’ seems to derive from an ancient principle found by the Buddha that there is no ‘self’ [attā] against other philosophical theory of several schools in India in which it is called ‘attaman’ in Sansrit. It is believed that before and during the time of Buddha, there was a view of the existence of ‘self’ whilst the Buddha later completely denied it.
He also argues that there is no ‘self’- It is merely a lexical creation of word to represent a conventional truth which we use to define and call things daily. Furthermore, he explains that ‘self’ in which we presume as our ‘body’ or ‘ourselves’ is merely the assembly of the five aggregates [paňca-kandhāni: rupa= corporality, vedanā= sensation or feeling, saňňā= perception, sangkhara= mental formation; volitional activities, and viňňāna = consciousness] in which, again and again, it is subjected alteration, uncontrollable, impermanent and decay at the end.  ‘anattatā’ as state of being not subjected to authority. For instance, we are not able to control or authorize the assembly of the five aggregates to last or sustain in the same condition for eternity; speaking of which, we cannot force or prevent the negative condition such as; pain, illness and aging that happen to our conventional ‘self’.
The principle of ‘the Three Characteristics’ is considered the common law of nature bound to the world we live in. It is believed that whether the Buddha emerges or happens in the world or not, this natural law always exist. Therefore, in some Buddhist traditions, the reverence of doctrinal principal is more accepted and emphasized than that of the personal- even the significance of Buddha. However, still, he is revered as the one who discovered, enhanced, and declared it to the world. Nonetheless, it seems the theory of ‘tilakkhan᷂a’ has been undergone through several alteration and enhancement through a long history since the time of the Buddha. Apparently the term seems to be more vividly described in the ‘commentaries’ era when Buddhist scholarly works sprung prosperously in Sri Lanka, Burma and Thailand approximately 1,000 years after the demise of the master. Buddha merely refers to these three characteristics by calling it ‘dhamaniyāma’ which appears in the ‘tipitāka’.