Motivation

Consider the following statements.

1. ``The situation at the beginning of the 100 meter race was the following: Alan is in start position one, wearing red clothes. Ben is in position two, wearing blue clothes. He is the favorite. Carlo and Denis are in position three and four.''
2. ``This is an embarrassing situation.''
3. ``The situation in Europe during 1914 and 1918 was critical.''
4. ``The situation in Europe in the year 1914 lead to the First World War.''
5. ``I would not have acted differently in the same situation.''
6. ``The situation on this x-ray shows, that the person that x-ray has been taken of had a broken leg.''
7. ``In the situation of a terrorist bombing, oil prices rise rapidly.''

All those statements claim to be about situations. In the first, a situation is characterized by certain statements, facts, that are the case in this situation. The second statement assigns an attribute, being embarrassing, to a situation. The third does the same, but clearly extends the situation over an interval of time, 4 years, and a certain region, Europe. The fourth refers to a certain situation as the cause of an event. One can refer to this event also as a situation, as the previous example shows. The fifth example connects a situation with some action, that has been performed in it. The sixth example describes a situation, that somehow seems to involve another situation, the situation where some person broke a leg. The seventh example refers to a situation as an instance of some concept, some general idea of a situation, the terrorist bombing, and also asserts a fact to it.

These examples show, that the term ``situation'' is used in several different meanings. Just what are the similarities, that lead us to the usage of this term? What do all of the above mentioned references to situations have in common? These question have to be answered in order to characterize an ontological category of situations. As important as the similarities are the differences of the references to situations above. The main distinction will be between those, that have a temporal extension, and those without. We will call the first ``situoids'', the latter ``situations''.

The examples show another aspect. Obviously, situations can be used to describe parts of the real world. But there are other ontological categories that can be described using situations. We mentioned some of them, events and actions. Both have been discussed before, and are frequently used together with, sometimes synonymously to situations. An intense study of situations should help us in the investigation of both, events and actions.

The fourth example refers to a situation as a cause of some event, possibly another situation. The study of cause and effect has been going on for centuries. The relationship between cause and effect is called causality. A study of situations, that may be causes, or effects, may lead to better understanding of the concept of causality.

The first example somehow characterizes a situation, by stating facts, that is, relations between certain objects in the situation. What a fact is, how it behaves and how and in what way it can occur in a situation is another issue, that may be solved by a study of situations. Facts are closely related to states of affairs, and the nature of existence, the ontology of states of affairs has been debated for decades amongst philosophers, and in the process of an ontological investigation of situations, the ontology of states of affairs has to be reviewed, too.

The seventh example refers to some concept, a certain situation may be an instance of. These concepts are called ``universals'' in philosophy. They are general ideas of concrete existing or abstract entities, that are its instances, and they usually determine certain properties of its instances, for example the fact, that oil prices rise rapidly in a situation of a certain type. Universals have an impact on situations, and have to be investigated when situations are.

Example six has some interesting properties. Obviously, there is a described situation, an x-ray of some persons leg, but due to certain properties of this situation, information about some other situation is revealed, the situation where a person broke a leg. Situations appear to be able to carry the information of other situations.

Situations can be described in natural language. All the examples above show this as a fact. We could ask the question, whether there are situations that are not describable in natural language. And another question can be asked, too, whether or not we describe anything other than situations, whenever we express our thoughts in words. Also, all of the above examples have to be uttered. This utterance-situation may be viewed as a situation, that defines the context of the uttered statement. Can this be used to give meaning to consecutive sections of text, like a novel? The answer to these questions and therefore a theory of situations may give valuable insight in the semantic of natural language.

Finally, all the examples above may indeed have something in common; we refer to situations as to special parts of reality, parts, that can be comprehended as a whole. What this means, will have to be investigated first.