Immaterialism is a theory which proposes that there are no material objects. This is often associated with Bishop Berkeley, an Irish philosopher. In the 18th century. Berkeley expounded that there are only ideas and minds; this is evident with his motto, “To be is to be perceived.” Hence, mental perceptions define reality. This belief dates back to the time of ancient philosophers such as Plato and Augustine as they referred to “immaterial” eternal Forms like the “Prime Mover” or the “First Cause” of the universe. Similarly, Christian theology posits God and the Holy Spirit as immaterial.