The oft-glorified 'pursuit of happiness' is, in the Vedantic view, an irrational and self defeating exercise.
It wouldn’t be inaccurate to say that happiness is an object of pursuit for all human beings regardless of our many cultural, social, and economic differences. No matter who we are, where we live, or what we do, we all want to be happy. Since the very beginning of human civilization, happiness has been one of the most important subjects of study for philosophers, psychologists, and social scientists alike. Countless theories exist on how to alleviate suffering and achieve happiness and an increasing amount of research continues to be done on this subject even today.
In this context, it is interesting that our very own Upanishads and the Bhagavad Gita have stated the cause and nature of happiness very precisely thousands of years ago. These texts are the source of Vedanta, a philosophy which is at the very heart of Indian culture. In the view of Vedanta, the various means commonly used by people to achieve happiness are completely irrational. Ordinarily, man assumes that happiness can be achieved through wealth, material possessions, social status, desired lifestyle or career, relationships and so on. But Vedanta dismisses them for the simple reason being that all of these are temporary and uncertain in nature:
श्वोभावा मर्त्यस्य यदन्तकैतत् सर्वेंद्रियाणां जरयंति तेजः ।
All these may not be there tomorrow, they are ephemeral in nature, and they exhaust the power of body, mind, and senses (thus further reducing the possibility of happiness). – Kathopanishad, 1.26
The Gita too states this fact succinctly:
ये हि संस्पर्शजा भोगा दुःखयोनय एव ते ।
आद्यन्तवन्तः कौन्तेय न तेषु रमते बुधः ॥
These sense-objects and experiences are wombs of sorrow, as they have a beginning and an end. The wise do not revel in them, Arjuna. – Gita, 5.22
Interestingly, modern research in the field of psychology has confirmed this very fact over and over again. The fear of losing what one has and the uncertainty involved in these pursuits reduces the possibility of achieving happiness through them. But then what is the solution? How is happiness to be found? To understand Vedanta’s view on the matter, let us take a classic Vedantic example:
A wave in the ocean was always unhappy. It saw other waves who were much bigger and stronger, it also saw the ocean which was so vast and powerful, and seeing all this it felt quite inadequate about itself. It felt insignificant also because its life was of only a few seconds. Feeling so limited and inadequate, it spent its life suffering. Had it known the truth about itself, that it is actually water, which is not limited to that tiny wave but is the truth of all the big and small waves, as well as the entire ocean, it would have been relieved of its suffering. It was the presumed inadequacy of self which was causing wave unhappiness and it is the rectification of this mistake that holds the key to its happiness.
Same is the condition of human beings. We see all the various possibilities that the world has to offer and we see others who have so much more than us and feel quite inadequate and insignificant about our self. We feel that even we need to acquire and accomplish all this to free ourselves from the inadequacy. This overpowering sense of inadequacy (which, by the way, is our own mental construct) and the struggle to free ourselves from it leads to our suffering.
But, in the view of Vedanta, this very assumption about our self is incorrect. It is based on sheer ignorance. It is based on taking oneself as nothing more than this limited and mortal body-mind complex. However, the reality is that the body and mind is only an assemblage of ever-changing and inert aspects of nature. Body and mind is not the real self. The self is pure consciousness which is unchanging, permanent, and immortal, and this consciousness is the truth of this one body and mind as well as the entire universe (just like water is the truth of wave and ocean).
So, if one stops considering oneself as an inadequate and limited being, and knows oneself as the limitless truth of it all, one would not need any object or experience of the world to be happy. If one knows oneself as such, one would be content and happy by one’s own self.
The Gita says:
प्रजहाति यदा कामान्सर्वान्पार्थ मनोगतान् ।
आत्मन्येवात्मना तुष्टः स्थितप्रज्ञस्तदोच्यते ॥
When all desires of the mind are defeated, one remains content by oneself. Such a person is said to be established in self-knowledge. – Gita 2.55
Therefore, in the view of Vedanta, happiness is because of the limitlessness of self. There is no other cause of happiness. It is only when a person stops feeling inadequate about oneself that he feels happy. It may seem that objects and experiences are causing happiness but it is our mistake. Let us see how:
Suppose a man wants to become the managing director of a company. He deeply yearns for this accomplishment. Without it, he sees himself as inadequate, unsuccessful, and therefore unhappy. Now suppose, one day he finally becomes the managing director. He feels ecstatic on that day. His happiness has no bounds. How did this happen? How did he experience this happiness? He experienced it because, for the time being, he stopped considering himself as an inadequate person. For the time being, that inadequate desirer in him disappeared. This resolution of inadequacy is what led to his experience of happiness.
Can we say that it was his newfound position which gave him this happiness? NO. He will have that position for many years but his happiness will vary through that time. If the position itself had the ability to make him happy, he should be happy all the time as long as he has the position. But this doesn’t happen. He is happy for a while only – only as long as that inadequacy doesn’t re-surface.
Here, it should be remembered that this inadequacy is the person’s own mental construct about himself. It need not be there at all. He sees someone in a higher position commanding power and wants to have that for himself. Because of this assumption, he feels inadequate about himself. He feels he cannot be happy without achieving his object of desire. Now, if he happens to achieve that object of desire, the ‘desirer’ is resolved – for the time being. This leads to him feeling happy.
In other words, when there is no separation seen between the desirer and the object of desire, happiness is experienced. So, happiness is the result of non-separation of the subject and the object which is only possible if the truth of both the subject and the object is one. Therefore, the limitlessness of self is the only cause of happiness.
This entire analysis is presented in the second chapter of the Taittiriya Upanishad titled ‘Ananda Valli’ – the chapter on happiness. At the beginning of the chapter, self is defined as ‘अनन्तं’ i.e. limitless. The chapter goes on to methodically present how self is limitless. Then the self is called ‘रस’ which denotes happiness  and it is said that one who knows the true nature of self, becomes happy:
रसो वै सः । रसंह्येवायं लब्ध्वानन्दी भवति ।
That (self) is rasa. Gaining it (i.e. knowing it), one becomes happy. – Tait. Up. 2.7.1
The very self is called happiness here because it is the limitlessness of self because of which one overcomes the sense of separateness and that is what happiness is really all about.
One can say that happiness is never really produced. It is already there as the fullness of one’s being. It is accidently discovered by us when we give up the ‘desirer’ on gaining an object of desire. The Upanishad, therefore, says that the main condition for happiness is अकामहतत्व  – not obsessed by desires.
The Upanishad goes on to state that happiness experienced by the ruler of the universe and an ordinary man are not really different in the sense that both have the same cause – the limitlessness of self.
स यश्चायं पुरुषे यश्चासावादित्ये स एकः
Self of this individual and the Aditya (i.e. Ishvara) is one. – Tait. Up. 2.8.5
The difference between Ishvara and an ordinary man is only apparent, just like the difference between the ocean and a wave. The truth or self of both is the same. And this limitlessness or wholeness of self is the cause of happiness for both. If this is understood, the whole orientation of one’s life would change. Presently, we are engaged in what is popularly known as “the pursuit of happiness”, where all our efforts are aimed towards achieving happiness through objects and experiences of the world. But when one sees the irrationality of it all and recognizes self-knowledge as the only way to happiness, one’s whole way of life changes. Bringing about this transformation in our lives is the aim of Vedanta.
Om tat sat
 रसो नाम तृप्तिहेतुरानन्दकरो मधुरअम्लादिः प्रसिद्धो लोके – Sweet-sour tasting food is well-known as ‘rasa’ and since these foods give contentment and happiness, ‘rasa’ is used to denote the same. – Shankara’s Commentary on the word ‘rasa’.
 Taittiriya Up. 2.7