One of the most common forms of abstraction is the notion of categorical thinking. Basically, we impose on phenomenal objects a meaning that we take very seriously, whether or not such an imposition is meaningful or not. For instance, the following objects could exist in the phenomenal universe. The question is, how are they related to one another in the “right” relationship. The first group is objects existing totally on their own, without bearing the burden of expectations or associations.

We can see they are familiar objects of different shapes, sizes, and colors. There is nothing particularly remarkable about them individually or as a group. When we introduce the idea of “order” to this collection of objects interesting things begin to happen. There are different ways to order these objects, from which we can derive certain conceptual distinctions.

The first way to order the objects is to classify them by shape. Among those shapes are stars, squares, circles, and triangles. There is no particular ranking inherent in the shapes. However, stars are often given as rewards to children, so there may be some experiential association that would suggest stars might be more appealing than the others.

Another way of grouping these objects is to distinguish them by color. Some are blue, some black, yellow, or red. Some colors are considered more appealing than others, however such things are simply matters of taste.

Size introduces a different sense of “order in the objects. Larger objects are often considered more important than smaller objects, even though all the other attributes remain the same.

A completely different class of differentiation is the idea of angularity. If one thinks that angles and straight lines are appealing, then those items with those features will be favored over the circles. On the other hand if angles are not attractive, then the circles will have the appeal.

A totally subjective way of considering these items is to think of the color as conveying “temperature.” Blue and black might seem to some to be “cool” colors, while red and yellow might be considered as “hot” colors.

Now which category of thinking is the “right” way or the “wrong” way to classify these items? In actuality, all such categories, however justifiable, are simply inventions we have imposed on individual items. The “order” is invented and all implications based on that invention are really abstractions. (See Abstractions).