Happiness must be cultivated. It is like character. It is not a thing to be safely let alone for a moment or it will run to weeds.
But the wicked passions of men's hearts alone seem strong enough to leave...
Science will explain how but not why. It talks about what is not what ought to be. Science is descriptive not prescriptive it can tell us about causes but it cannot tell us about purposes. Indeed science disavows purposes.
