A wise man once asked a less wise man, "Is that rock heavy?" He was pointing at a very large boulder. The less wise man said, "Yes." The wise man looked at him and replied, "Only if you pick it up." The moral of the story is that many of the qualities that we assign to objects (e.g., heavyness) are really psychological phenomena that exist only within the organism that is experiencing them. To see this more clearly, imagine a three year old picking up a grocery bag. Here, the three year old experiences "heavyness," while the adult does not. The bag is not heavy; heavy is a propery of the biological being experiencing the bag. In this class, I will introduce you to your brain. Say hello and be polite.