800. Just as one can juggle with the matter or the details in the "outer" world in order to be able to promote one's instinct of self-preservation – animals obtain food and promote their urge to mate, and human beings do the same as well as having the beginnings of a higher juggling with matter in the form of so-called "artistic creation" – one can also juggle with the material of the "inner" world. We can "move around" or "change" something in all the many impressions we have received through our senses from the "outer" world. If we have seen a church with one spire, we can provide the "inner" copy of this sight with two spires. We can also supply this "inner" copy with more windows or more wings than found on the "outer" picture that the church represents to our senses, just as we can also change the inside of the church on our "inner" copy. We can, for example, give it quite different furnishings and totally different spatial dimensions than that which appears in our original, "inner" copy of the church. In the same way, we can alter all our other "inner" copies. We can reduce them, change the details and make them plainer or more perfect, according to our own ideas of perfection. This juggling with the matter and details of the "inner" world we express as the "functioning of thought" or "mental work".