follow them quickly in order to catch or reach them.
She chased the thief for 100 yards...
He said nothing to waiting journalists, who chased after him as he left. = pursue
If something that you want eludes you, you fail to obtain it.
At 62, Brian found the celebrity and status that had eluded him for so long.
If you elude someone or something, you avoid them or escape from them.
He eluded the police for 13 years.
If a fact or idea eludes you, you do not succeed in understanding it, realizing it, or remembering it.
The appropriate word eluded him. = escape
A variety of biological, psychological, religious, and philosophical approaches have striven to define happiness and identify its sources. Various research groups, including positive psychology, endeavor to apply the scientific method to answer questions about what "happiness" is, and how it might be attained. It is of such fundamental importance to the human condition that "life, liberty and the pursuit of happiness" were deemed to be unalienable rights by the United States Declaration of Independence.
Philosophers and religious thinkers often define happiness in terms of living a good life, or flourishing, rather than simply as an emotion. Happiness in this sense was used to translate the Greek Eudaimonia, and is still used in virtue ethics. Happiness economics suggests that measures of public happiness should be used to supplement more traditional economic measures when evaluating the success of public policy.
Happiness is a fuzzy concept and can mean many different things to many people. Part of the challenge of a science of happiness is to identify different concepts of happiness, and where applicable, split them into their components. Related concepts are well-being, quality of life and flourishing. Some commentators focus on the difference between the hedonistic tradition of seeking pleasant and avoiding unpleasant experiences, and the eudaimonic tradition of living life in a full and deeply satisfying way.
The 2012 World Happiness Report stated that in subjective well-being measures, the primary distinction is between cognitive life evaluations and emotional reports. (Emotional reports can be distinguished as of positive or negative affect. Many but not all commentators regard positive and negative affect as carrying different information, and needing to be separately measured and analyzed). Happiness is used in both life evaluation, as in “How happy are you with your life as a whole?”, and in emotional reports, as in “How happy are you now?,” and people seem able to use happiness as appropriate in these verbal contexts.