A concept is a particularly significant resident of Foxspace—something with a shape, a word with a definition. These thoughts have exceptional influence over the layout of this space, as they serve as the origins and destinations of other thoughts. They are also immutable references; the attributes of the things they describe may change over time, just like person’s personality or appearance, but what they describe cannot—Foxspace as a space may change completely, but the concept of “Foxspace” will never refer to anything else but itself.