interesting clip!

The opposing view, of course, is that if there are multiple theories that explain the same phenomenon, they should all be considered since they offer multiple points of view and possible means of extension beyond that of a single unified theory. In other words, we typically have a unified theory and then try to extend it step-by-step in different directions. If we had multiple theories explaining the same phenomenon, then extension would be possible by branching out from more than one starting point.

For instance, if you have a theory that the increase in the well known absorbance of infrared by carbon dioxide due to the well known increase in carbon dioxide in the atmosphere due to the well known combustion of fossil fuels over the past few decades is the cause of the well known increase in global average temperature over the past few decades, versus a theory that some unknown thing is preventing this effect which you would expect from burning all that carbon, and some other unknown thing is what is raising the temperature; then you'd go with the theory which involves fewer mysterious unknown things.

http://www.savagechickens.com/images/chickenrazor.jpg