And this brings the course to an end. In this course, we've basically reviewed all of psychology, some more in-depth than others but you have a feeling for the whole field, and you're now in a position to answer questions about memory, depression, language, child development, how the brain works. You have some sense of why people are different and have different personalities. You have some understanding of the social influences on our lives, what makes us afraid, what leads to different forms of mental illness. You even have a little hint on what factors influence our happiness, and maybe you could use your knowledge to make you a little bit happier, yourself. Now, the field of psychology is broad and we've just gotten started, but for some of you, this will be the last course you ever take in psychology. So, I want to end this course by focusing on two things. The first is a bit of humility. There are some very basic questions about the mind that nobody knows the answer to yet. We know that the brain is the source of mental life, but we don't have any real understanding of how a physical object, a lump of meat, can give rise to conscious experience. We haven't yet solved what philosophers call, the hard problem. We know that about half the variation in personality is a result of genes, and so too for intelligence and happiness, and many other things, but we don't really know how to explain where the other half comes from, what experiences make us what we are. We know about the social influences that can make us do certain things, including bad things, but we don't yet know why some people are immune to these influences, and act and sometimes do great and heroic things, regardless of the circumstances that they find themselves in. So, there's a lot left to do. But the second theme is more optimistic. This is the idea that will eventually come to answer these questions, to solve these problems, through the methods we've been discussing, through the series of lectures. This is the idea that in the end, the most important and intimate aspects of ourselves, our beliefs and emotions, the capacity to make decisions, our sense of right and wrong, can be explained through constructing, and testing scientific hypothesis. I think there's been some success stories where we really have learned some surprising and important things about the mind, and there's no reason to expect this way of proceeding to fail us in the future. Now, some people may find this a scary prospect. I know that some people worry that a scientific approach to the mind takes a specialness away from people, it diminishes us somehow, but I don't agree. I have the opposite reaction actually. My view is the more you look at the mind and how it works from a serious scientific point of view, the more you appreciate its complexity, its uniqueness, and its beauty. And I'll end with that.