Denny,
You are looking at geography in too limited a fashion, I believe that you are equating it with cartography, or the type of geography that we learn in high school, Indianapolis.is.the.capitol.of.Indiana...Actually, geography would give you as good a chance at answering your question as any discipline since geography looks at the relationship of man and environment.  This often has a cartographic component and geographers are great ones for maps, but these maps can get pretty sophisticated.  There are maps that show population density, ethnic concentrations and mixtures, energy usage, crop types, religious affiliations, political divisions, annual income per capita, traffic density, and a dozen other things that can be presented spatially, and that can be composed to show these factors over different times.

If you overlay a general map of Eurasia with the specific types of maps above you would get broad pattern of agreement in-though not complete or perfect alignment by any means with-the general notion of Europe.  That would just be a starting point for the more significant question, which I think that you are asking, which is, who are you people who live in this large area?  Is there a set of commonalities between you that differentiate you in important ways from those of us who do not live there?  If there is a set of commonalities is it a result of facts on the ground, or is it an outlook based on ideas?

From across the Atlantic, it looks more and more that an European identity is coming into being, again.  From afar it appears that the history, the political organizations, and the economics are being expressed with a sufficient cohesion to at least superficially express a specific and identifiable grouping of people.  In the dark hour we are going through here, we hope both that people can see all the things that we have in common that are not expressed on these maps, and that Europe, whatever it is, stands for enlightenment.  

"I said, 'Wait a minute, Chester, You know I'm a peaceful man...'" Robbie Robertson