Essence of Love
The essence of love is alternately and at the same time psychological, philosophical, physiological, religous and scientific.
Defining it is therefore somewhat difficult to pin down; but Wikipedia tries with "a number of emotions and experiences related to a sence of strong affection and attachment".
Not bad for one sentence; but time and many analytical disciplines have greatly expanded the concept; and we will also, but briefly.
Emotions we experience in connection with it may include caring, passion, desire, lust, intimacy, closeness, profound oneness and devotion, among others.
It may be impersonal (of country; or I love my sports car) and/or interpersonal (human relationships; I love my sister)
Psychology generally views it as cognitive, social and cultural, influenced by passion, longing.
Biology sees it more as a drive or hunger, influenced by hormones and thought.
Philosophy, religion, and art have throughout time depicted it most profoundly.
The essence of love, while complex and abstract, remains universal and captivating.