Happiness is perhaps most usefully described as the absence of unhappiness.
Happiness is not to be found in self help books. Happiness is not the reward of an imaginary god for following the ways of righteousness. Happiness is an emotion. It is a consequence of consciousness. It is a quale. It almost certainly has a physiological basis as well as a subjective and more elusive cause.
It is helpful to distinguish happiness from a state of euphoria. States of euphoria are often described by mystics and can be seen as a transcendence of normal reality – an elevation to another plane of existence perhaps, real or merely perceived.
Happiness is best thought of as a more “normal” state of affairs and certainly more “easily” achievable. But perhaps less easily “sought”. We know how to seek euphoria. We know that it can be attained through meditation and sometimes through an intense reaction to something physical such as music, nature or art. We know that euphoria can be achieved through the use of drugs such as DMT or phycobilin.
So far as we know states of euphoria are temporary phenomena – not sustainable over long periods of time. Although we may wish it were otherwise. Happiness by contrast (certainly as defined by the absence of unhappiness) can continue for prolonged periods.
If happiness is the absence of misery then we need to eliminate misery. Misery can be caused by hunger, pain, loneliness and many other negative emotions such as envy, hatred and anxiety.
Hunger can be avoided by meaningful work – meaningful because a lack of meaning in our work can in itself be a cause of unhappiness. Physical pain can often be treated by medicine but sadly not always.
Hatred and envy may be a matter of choice: do we have to feel envy? Do we have to feel hatred? These may be areas where we can change our mind and our behaviour for the better.
Above all we need to realise that we do not fully understand emotions and can not entirely explain them. Modern science tends to take a reductionist view of the matter – emotions are physiological and the neural correlates of happiness can be read by an MRI machine.
You are left therefore with trial and error. A satisfying occupation, good nourishment, health, physical exercise, beneficial social interaction are all factors which may help to combat negative emotion. Being fully engaged in a satisfying life may be as close as we will ever get.