According to Drs. Francomme and Penoel
(from Phytoguide No.1: Advanced Therapy for Infectious Illnesses):
Plant essences, in the physiological meaning of the term, are most certainly true life essences, elaborated by the secretory cells of the plants which have tapped the photo-electro-magnetic energy of the sun and have converted it, with the intervention of enzymes, into biochemical energy under the form of highly diversified aromatic molecules.
Essential oils are highly concentated forms of plant energy. ... One drop of rose oil contains the energy from 30 roses, and one drop of essential oil is said to have the theraputic value of 25 cups of herbal infusion.
I never thought of essential oils as having energy per se. I knew they had "powers", but have never thought of them as being alive in the way described above. I thought once the essence had been extracted from the plant, the life sort of left them, but its seems that they evolve into a new form of life - as though the power/spirit of the plant was pulled out of its body. I guess the essential oils are the "souls" of the plants.
There is too much to learn in too little time.