The primary activity of the left brain is deconstructing the world and using the resulting pieces to construct new worlds. This is the primary method of all human creativity. It's sounds a lot like playing with Legos, and it is, but there are crucial differences. In this post I want to describe the world of the left brain, just as I described the world of the right brain in the preceding post.
People are playful. We tend to think of playfulness as some sort of icing on the cake of humanity, but I believe it is fundamental. Not everyone is playful all the time. Nor do our histories talk much about play; they tend to concentrate on the serious business of survival and power. That may be what history is about, but day-to-day life is about play.
This is not to say everyone's life is fun or even that most people's lives are fun. Fun isn't the reason we play. The reason we play is that we have no choice; it is our nature.
One primary activity of the left brain is exploring the world. The right brain typically starts this process by moving the head and eyes so the central right visual field encompasses something interesting. The first thing that happens is that the left brain finds boundaries in the visual field and interprets the space between and outside the boundaries as pieces of the world. The left brain carries around a lot of re-presentation of previously found objects. A re-presentation is a somewhat idealized memory of a class of objects, something akin to an icon. That is, the first time the left brain sees an object it remembers it much as it was first seen. After seeing additional versions of the object, it forms a more general image of the object that both represents the object and re-presents it in slightly altered form. If a first level object is not recognized, the left brain will typically, look for boundaries in it, and continue the decomposition. For example, the first time a person sees what might be a house in the distance, the left brain identifies the roof, walls, doors, windows, etc.
Once the visual field has been decomposed into recognized pieces, the left brain will hold the pieces in relation to one another and see if the pieces can be recognized as some reconstructed whole. The left brain also carries around a lot of reconstructed wholes. Again, these are re-presentations of classes of real objects. Continuing the example, the left brain that sees the erstwhile house will discover that an object with a roof on the top and walls on the side, with windows and doors, is likely a house. If the match is sufficiently decisive, the left brain will "decide" that it is a house and start deconstructing its constituent parts, discovering how the roof, walls, windows and door are constructed. If the match isn't decisive, it may continue looking for matches to a whole and find perhaps "barn".
We can see these re-presentations by asking people to draw something that is not present. "Draw a house". Most people will draw an image of their left brain re-presentation of a house rather than a specific house. This left-brain re-presentation will typically be recognizable to others, but won't be considered particularly artistic. In fact, the drawing may be a better picture than what they carry around in their head because during the drawing we will be fixing obvious deficiencies like "shouldn't the walls and the roof meet?"
These collections of re-presented parts and wholes are the Lego-like building blocks the left brain plays with. When the left brain isn't doing anything else, it creates new things from these pieces, and some of these new things are added to the collections of wholes that might be found during some later exploration.
Note that the re-presentations aren't really stored as parts and wholes. We continually deconstruct and construct so that most parts are really constructed of smaller parts, and wholes are often constituent parts of more grandiose wholes. Thus we understand that doors are really made of molecules, atoms, nuclei, quarks, fields, etc., and are parts of a house in a great city on a planet in a solar system in a galaxy in one of many possible universes.
One form of creativity is seeing things that others don't see. This may result from a person having imagined (mentally constructed) something before others had actually seen it. Another form of creativity is making a physical representation of an imagined something that has never existed before, even if it just a little bit better than something that did.
The reality of a creation is perceived by the right brain and made an important part of our right-brain reality and that of others around us. Thus the creative process that started with the right-brain directing the visual field of the left brain to something "interesting" proceeds full circle to returning the fruits of creation to the right brain. This enables the right brain to find more "interesting" somethings to direct the left brain to play with.
Traditionally, creativity is ascribed to the right brain while I have described it as a playful partnership of both hemispheres. These observations are not really in conflict if you understand what artists and philosophers have been telling us forever: the foundation of all creativity is perceiving the world clearly. They tell us that by this they mean seeing the world without the veils that cloud our vision and distort reality. The right brain sees clearly, but few of us are brave enough to trust its view over that of the more familiar re-presentations that fill our minds. So for most of us, trusting the right brain is at once the most creative act we will perform and the basis of all further creation.