Inventions are things that are new or that serve a purpose which has not been served previously. When the can opener was first invented it probably consisted or a sharp stick and a rock. There are a variety of invention quotes that show the promise that mankind has for ingenuity and creativity, and some of the best and most useful inventions are born of necessity. When a new machine or innovative product is first thought of and created it is necessary to get a patent to protect the interests of the inventors. Without a patent any new inventions can be used by anyone without any payment at all, or someone else could try to patent the inventions that they did not help design or create.