The point is that you don't know about the people who were just as smart and worked just as hard, so you have no way of judging. Ability and hard work are neces

The point is that you don't know about the people who were just as smart and worked just as hard, so you have no way of judging. Ability and hard work are necessary but not sufficient conditions. To disprove that thesis, you'd need a complete sample of people with ability and hard work and, before you know the outcome, be able to select who would succeed.