body: First situation:
  
  
  Out of curiosity about what the living room in a house looks like, you notice that while the inhabitants are not home a door is unlocked, so you enter and look at the living room and then leave.
  
  
  If I understand correctly, that is tresspassing, which is a misdemeanor.
  
  
  Second situation:
  
  
  Same as above, but instead of curiosity about what the living room looks like, your purpose is to smash a flower pot that you happen to know is in the living room.
  
  
  If I understand correctly, when this kind of trespass is for the purpose of committing some additional crime besides only trespass, then it's burglary, which is a felony.
  
  
  Third situation:
  
  
  Like the first situation above: your only motive is to see what the living room looks like. But while there, on a sudden whim, you decide to smash a flower pot that you see in the living room.
  
  
  This time the trespass was not for the purpose of committing the additional crime, but still the additional crime happened and would not have been possible without the trespass.
  
  
  Is it burglary then?
  
  
  
title: The nature of burglary