A scientist is one who has learned to prepare his knowledge. The main difference between a scientist and one who is not that the scientist sees the significance of facts, while the non-scientific, man sees the facts as more or less unrelated things. As one comes to hunt for causes and inquires into the significance of things, one becomes the scientist. A factor or an event always points beyond itself, to something else. This something else is what goes before it or comes once it, is its cause or its effect and impact. This causal relationship which exists between events enables a scientist to prophesy. By carefully deciding what always precedes a certain event, a certain type of happening. A scientist is able to predict the event. All that’s necessary to be able to predict an event is to have a clear knowledge of its true causes. Whenever, on the far side any doubt, these causes are found to be present, the scientist knows the event will follow. Of course, all that he really knows is that such results have always followed similar causes in the past. However, he has come to have faith in the uniformity and regularity of nature.