There exists a strong relationship between philosophy and cognitive science. In the past, great philosophers sought to answer many of the major questions that cognitive scientists ask today. Philosophy’s preoccupation with understanding concepts such as knowledge, the mind, and consciousness has created important foundations for modern-day cognitive science. Classic philosophical questions such as “What is the source of knowledge?” and “What is reality?” are now being re-examined by cognitive scientists. Today, philosophy and cognitive science feed off of each other. Cognitive scientists use philosophical concerns as a jumping-off point for their research, but additionally, progress made by these scientists affects the credence attributed to different philosophical viewpoints. As new discoveries are made, the pendulum swings towards one classic theory, and away from the opposing one. However, until cognitive science finds definite answers to its questions, philosophical theorizing and its competing perspectives will always have an important place in this modern field.