DOYLC

Stijn made a couple of sharp points in a comment on the post How is a Definition Different from an Explanation? (Part 1) (http://definitionsinsemantics.blogspot.com/2011/11/how-is-definition-different-from.html).  He notes that there is a need for definitions to be short in certain circumstances, as when a user is scanning through a list.  I think this is a good point.  Users may be more in search mode when they are doing something like this.  They want to know if the definition is close to some target they have in mind.  Obviously, a full definition is not fit for such a purpose. So we might have three levels of definition: (a) a one-liner, suitable for lists; (b) a one-paragraph, suitable for a quick read with some detail - and display on a screen with scarce real estate; and (c) the full definition, as an authoritative reference.  I have no problem with the last one being very long and including pictures - certainly more than half a page.  ...

In Part I of this series (http://definitionsinsemantics.blogspot.com/2011/11/how-is-definition-different-from.html), we explored explanation defined as "bringing a mind to an understanding of a topic".   There is, however, another form of explanation, of which Aristotle said "We believe ourselves to know a thing when we are acquainted with its cause" (Posterior Analytics, II C. II para 1). One way to provide this kind of explanation is by arguing from the cause to the effect.  Traditionally this involved using syllogisms where the cause was in the major premiss and the effect was in the conclusion.  E.g. All ellipses show a pattern of positions X; the orbit of Mars shows a pattern of positions X; therefore the orbit of Mars is an ellipse. This form of explanation is very satifying, and it might seem natural to try to incorporate it into definitions.  However, there are reasons not to do so.  First, the above form requires putting the concept to be defined i...

This topic will require more than one post, because there is more than one definition of "Explanation".  That is, the term "Explanation" signifies more that one concept. The first kind of explanation we will deal with can be defined as: "Bringing a mind to an understanding of a topic". This means that an explanation must be relative to the mind which is to be brought to the intended understanding.  For instance, the way we explain the solar system to an 8-year old child will likely be different to the way we explain the solar system to a college undergraduate.  The explanation offered will depend on prior knowledge, experience, developed intelligence, and probably many other factors.  Differences between defintion and explanation can be summarized as follows: A definition is not intended to be proportional to any mind.  It has to be the best description of a concept that is available. This is is quite unlike explanation, where there will be many explanatio...