can you isolate energy so that it can’t be classified [into things like electrical energy and thermal energy] and was

Question: can you isolate energy so that it can't be classified [into things like electrical energy and thermal energy] and was just pure energy? If so, would it do anything? Would it do everything (give out heat,light, etc)? If not, then what is energy?
- Keywords:
  energy
Asked by Zealousy to Chris, Josh, Rebecca, Rob, Susan on 17 Jun 2015.
- Susan Cartwright answered on 17 Jun 2015:
  
  No, there’s no such thing as “pure energy”. In relativity, energy and momentum are linked into one thing (the “energy-momentum four-vector”). It would make no sense to talk about “pure momentum” – momentum is a property of an object – and in the same way it makes no sense to talk about “pure energy”.

Question: can you isolate energy so that it can't be classified [into things like electrical energy and thermal energy] and was just pure energy? If so, would it do anything? Would it do everything (give out heat,light, etc)? If not, then what is energy?