S1: Many hands make light work. S2: Too many cooks spoil the broth. The second sentence:

The first proverb says that more people working together makes work easier. The second proverb warns that too many people can ruin a task. The second sentence doesn't directly contradict the first - both can be true depending on circumstances. It adds a condition: cooperation helps, but only up to a point. This is qualification - placing a limit on the first assertion. Therefore, the second sentence qualifies the assertion of the first.