To know something, says Aristotle, one must know its causes. For Aristotle, knowledge of causes provides an explanation. It's a way to understand something. Because of the importance of causality to knowledge and understanding, Aristotle developed something like the comprehensive doctrine of causality, distinguishing efficient, material, formal, and final causes, and subsequent concepts of causality have been derived from his analysis by omission. Aristotle's four causes give answers to questions about the thing to help ascertain knowledge of the thing, such as what the thing is made of, where the thing comes from, what the thing actually is, and what the purpose of the thing is. The purpose of the thing is used to determine the first three, in addition to the fact that the purpose is basically the same as what the thing actually is, as the purpose of the thing is used to determine whether a thing is what it is or not. The first cause necessary to acquire knowledge of a thing is the material cause. The material cause answers the question “what is the thing made of?” It is the “of which”. An example would be a car. A car itself is made up of a variety of different materials including metal, glass, rubber and plastic. Metal makes up the body and engine, glass makes up the windows, rubber makes up the tires, and plastic makes up the car's interior components, such as the dashboard. All these materials are used in the production of a car. The next cause is the efficient cause. Efficient cause answers the question “where did the thing come from?” It is the “from which”. The car begins as a thought in the mind of an automotive designer, the designer then sketches out the shape of the car in a design blueprint… in the middle of paper… because it is used to answer “what?” is the point?" And finally the final cause is used to establish "what is the purpose or function of the thing?" In the example of the car, its material cause was the metal, rubber, glass and plastic of which it was made. The efficient cause was the designer who designed the car and the factory where it was assembled. The formal cause was that it was actually a car because it had four wheels, an engine and could to transport people. And the final cause was that its function was to transport people from one place to another. The final cause is of crucial importance as it determines the first three and can be used interchangeably with the formal cause, since “what” cars and “why” cars are basically the same thing. Now you can use and apply these four causes in your life to gain knowledge and understanding of things.