Can you differentiate between an Abstraction and a Lie ?

In the June 2007 issue of Communications of the ACM, David Parnas differentiates between an abstraction and a lie. He mentions that abstractions that embody unrealistic assumptions represent nothing at all. He learnt the correct definition of abstraction from the late E. W. Dijkstra :

An abstraction is one thing that represents several real things equally well.

And he concludes ..

Finding the simplest model that is not a lie is the key to better software design.

So true, and how lucidly expressed! Go read the full article here. [Membership required for full text].