An endangered species is a species of organisms facing a very high risk of extinction. The phrase is used vaguely in common parlance for any species fitting this description, but its use by conservation biologists typically refers to those designated Endangered in the IUCN Red List, where it is the second most severe conservation status for wild populations, following Critically Endangered.
I measure my happiness 2 ways. 1  Through a (random and irregular) process of self reflection.  2 Catching myself being happy and remembering the last time I caught myself being happy and trying to determine the time between them.
In conclusion, according to Aristotle, what is happiness? Happiness is the ultimate end and purpose of human existence; Happiness is not pleasure, nor is it virtue. It is the exercise of virtue. Happiness cannot be achieved until the end of one's life. Hence it is a goal and not a temporary state. Happiness is the perfection of human nature.