(Originally published at www.catapultlearning.com)
(I use Grammarly for proofreading because I'm not as prefect as I might thing. Try it: www.grammarly.com)
In the world of logic, people talk about necessary and sufficient conditions. A necessary condition is anything that has to happen for an effect to take place. You cannot walk without certain muscles being contracted. Those muscle actions are necessary conditions. But those muscles will not, by themselves, make walking happen. When all of the things that have to happen, do happen, then we have what we call sufficiency. When you have a piece of the puzzle, but not the whole puzzle, you can say the conditions are necessary but not sufficient: I have what I need, but not all that I need.