Must a Definition Include Identification of Related Concepts?

The traditional answer to this question is "yes", because classic essential definitions follow the formula Definition = Genus + Specific Difference.

However, definitions of concepts in natural science tend to be more like descriptions than classical definitions.  This may be unavoidable, but there is always a danger in a descriptive definition of not mentioning any related concepts.  Such definitions may give the impression of a style in which definitions should be written, and this sometimes carries over into analyst work - so that some analysts tend to write descriptive definitions, even if essential ones could be provided.  And such definitions lack mention of related concepts.    

But should a definition always identify related concepts?  I think it should.  I think that practical usage of a definition requires an understanding of the Concept System in which the definition is located.  Without such an understanding, the user runs a risk of not being able to use the definition adequately.  I will have to return to this to offer a proof in the future. 

The Concept System itself is a concept.  Merely identifying the Concept System may be at too high a level of generalization - but it is better than nothing.  Better would be to find a proximate superordinate genus (an immediate parent supertype) within the Concept System, but this may sometimes be difficult.

A concept need not have just one relation (to the Concept System or a higher-level concept within it).  It may have other relationships.  Identifying such relationships in definitions will be helpful too.  This is a topic that leads to matching definitions to Conceptual Models, which we will have to return to. 

Therefore, I think that we have an additional quality assurance point for definitions: a definition must identify a superordinate genus within the Concept System in which it is located, or identify the Concept System itself.

A futher quality assurance point might be that a definition must identify all relations between the concept being defined and other relevant concepts - but this point needs to be followed up in a future post.

This leads to the consideration that a definition of a concept will change depending on the Concept System it is located in, and one concept can be located in more than one Concept System.  And that it yet another topic for a future post.