The Buddha admonishes his disciples to analyze the whole of the conception of self or abiding personality and thereby the whole of experience (loka) along with every single inherent component of the process, whereby the fallacy of self or abiding personality, viewing this whole process of the arising of nama-rupa [will become clear] in a perfectly objective manner.

From sight and physical objects arises visual consciousness, and the meeting of all three is contact, from which through contact with characteristics of existence come feelings, which may be pleasant or unpleasant or neither. When experiencing a pleasant feeling, a man rejoices in it, hails and clings tight to it, and a trend of passion (attachment) ensues.

When experiencing an unpleasant feeling, a man sorrows, feels miserable, wails, beats his breast and goes distraught and a trend of repugnance ensues. 

When experiencing a feeling that is neither pleasant nor unpleasant, he has no true and causal comprehension of that feeling’s origin, disappearance, agreeableness and outcome, and a trend of ignorance ensues. 

It can never possibly result that without first discarding the pleasant feeling’s trend to passion, without first discarding the unpleasant feeling’s trend to repugnance, and without first getting rid of the neutral feeling’s trend to ignorance, without discarding ignorance and stopping it from arising, he will put an end here and now to dukkha, and what is equally true of sight is true of the other five senses.

If we contemplate even a minute sector of life’s vast range, we are faced with a variety of living forms so tremendous that it defies description. Yet three basic features can be discerned as common to everything that has animate existence, from microbe to man, from the simplest sensations to the thoughts of a creative genius: (i) first, impermanence or change (anicca), (ii) second, suffering or unsatisfactoriness (dukkha) and (iii) third, non-self or insubstantiality (anatta). . . .

The Buddha applies the characteristic of suffering to all conditioned things in the sense that for living beings, everything conditioned is a potential cause of experienced suffering and is at any rate incapable of giving lasting satisfaction. Thus the three are truly universal marks pertaining even to what is below or beyond our normal range of perception.

The Buddha teaches that life can be correctly understood only if these basic facts are understood. And this understanding must take place, not only logically, but in confrontation with one’s own experience. Insight wisdom, which is the ultimate liberating factor in Buddhism, consists in just this experiential understanding of the three characteristics as applied to one’s own bodily and mental processes and deepened and matured in meditation.

To see things as they really are means to see them consistently in the light of the three characteristics. Not to see them in this way, or to deceive oneself about their reality and range of application, is the defining mark of ignorance (avijja), and ignorance is by itself a potent cause of suffering, knitting the net in which man is caught—the net of false hopes, of unrealistic and harmful desires, of delusive ideologies and of perverted values and aims.

Ignoring or distorting the three basic facts ultimately leads only to frustration, disappointment and despair. But if we can learn to see through deceptive appearances and discern the three characteristics, this will yield immense benefits both in our daily lives and in our [mental] striving [for higher states].

On the mundane level, the clear comprehension of impermanence, suffering and non-self will bring us a saner outlook on life. It will free us from unrealistic expectations, bestow a courageous acceptance of suffering and failure and protect us against the lure of deluded assumptions and beliefs. In our quest for the supra-mundane comprehension of the three characteristics will be indispensable.

The meditative experience of all phenomena as inseparable from the three marks will loosen and finally cut the bonds binding us to an existence falsely imagined to be lasting, pleasurable and substantive.

With growing clarity, all things, external and internal, will be seen in their true nature: as constantly changing, as bound up with suffering and unsubstantial, without an eternal or abiding essence. By seeing thus, attachment will grow, bringing greater freedom from egoistic clinging and culminating in Nibbana, mind’s final liberation from suffering.