All men seek happiness. This is without exception. Whatever different means they employ, they all tend to this end. The cause of some going to war, and of others advoiding it, is the same desire in both, attended with different views. The will never takes the least step but to this object. This is the motive of every action of every man, even of those who hand themselves.
Blaise Pascal
it is the law of the human heart, as gravity is a law of nature..
Pascal goes on to say:
There once was in man a true happiness of which now remain to him only the mark and empty trace, which he is vain tries to fill from all his surroundings, seeking from things absent the help he does not obtain in things present. But these are all inadequate, because the infinite abyss can only be filled by an infinitive and immutable object, that is to say, only by God Himself.