Energy is an abstract notion that helps to understand the nature and contributes to the creation of the civilization. The energy notion has a huge meaning not only due to practical reason – it is essential for economy and philosophy too. It turns out that in Hellenic philosophy, and especially in its fundamental part, i.e., metaphysics, there is no place for the concepts and methods of reasoning developed by physics and chemistry. Philosophy assumes that most of the physical and chemical concepts are not known in nature in spe these are employed by science only as a kind of mental keys (qualitative occultea) for the description and understanding of the universe. The concept of energy is only one example of a notion accepted both by the phi...