How do you best respond to life's unjust setbacks?
Quite simply, cognition refers to thinking. There are the obvious applications of conscious reasoning—doing taxes, playing chess, deconstructing Macbeth—but thought takes many subtler forms, such as interpreting sensory input, guiding physical actions, and empathizing with others.
Ah, happiness, that elusive state. Philosophers, theologians, psychologists, even economists, have long sought to define it, and since the 1990s, a whole branch of psychology—positive psychology—has been dedicated to pinning it down and propagating it.