What is Energy

Is it correct to say that the core idea of energy as the ablity to do work is the same for Newtionian Physics and Relativity?

 

mass is the measure of resistence changes in motion...hence, the capacity to do work is the same as the measure of resistance to chances in motion

 

I am writing a paper on the philosophy of science and I am arguing that the core concept of energy (the ability to do work) is the same for Newtonian Physics and Relativity and that the primary difference is that Einstein discovered the connection between mass and energy which was unknown to Newtonian science. Do you agree with this?

 

If you believe that use of such terms as 'core' and 'primary' are a matter of opinion then I withdraw them. I am interested in matters of scientific fact. Please bear in my mind that i am not asking whether the defintion of energy as the ability to do work happens to apply to Newtonian Physics and Relativity. I am asking how those terms are understood and function from a Newtonian and Relativistic veiwpoint.

Suppose that I re-phrase the statement this way...

the concept of energy (the ability to do work) is common to Newtonian Physics and Relativity and the critical difference is that Einstein discovered the connection between mass and energy which was unknown to Newtonian science. or do you believe that this statement is open to debate?

More specifically, i am interested in what changed and did not change in the concept of energy with regard to Newtonian Physics and Einstien.