Finally, I’d like to finish this lesson with talking about philosophy a little bit. And these insights come from the Danish Design researcher Piete En, and he is relating the process of software design to the thinking of four important philosophers. So, first philosophers, Descartes. We think about Descartes with analytic geometry. And this may translate for us into thinking about the analysis phase of software design. On the other hand, Marx is very concerned with social processes and classes. And understanding the social context of design, maybe even involving the users in the design process. Martin Heidegger, was concerned, among other things, with tools. And of course, tools play a big role in the automation of our development process and tools like IDEs in our active development environments and case tools, computer aided software engineering tools of course play a big role. And finally, my favorite is Wittgenstein, the Austrian philosopher, who came up with the concept of language games. And, what this means, is the inventing of a vocabulary, that helps you think about a particular problem. For example, think about the introduction of personal computers and the role that thinking, the role of the terminology of the desktop, folders, trash baskets, and so on, play in doing that.