Science has no definition for love. There’s even a real scientific debate over whether or not love is an emotion at all.
The Surprising Reason Brain Science Won’t Change Your Life (written by an ex-neuroscientist)
Chris Danilo

Sternberg’s triarchic theory of love is a nice attempt. It proposes that love has three components, something like passion, commitment, and intimacy. Many relationships follow patterns where love feels more or less like each of these three factors over time. The classic Western pattern has passion spiking first, intimacy rising soon after and commitment setting in later and lasting the longest.

You can imagine how an arranged marriage would follow a very different pattern, and may have different salient factors entirely. Sternberg’s triarchic theory is culture-bound, but I think the factorial model underneath the theory is still the right way to go.

The Ancient Greeks were onto this model millennia ago. They had no fewer than 5 words for love, including love through play (ludos), and unconditional love for all (agape). Sternberg’s passion is something like Greek eros, commitment is pretty much synonymous with Greek pragma, and intimacy is close to philia. Any loving relationship could be analyzed according to these factors, producing a wide range of possibilities for love.

I absolutely agree that love is not a true emotion, but a more powerful social force that seizes emotions and bends them to different purposes, each love acting according to its particular composition. Love does more than simply provoke emotional responses, it overtakes the whole “mood” filter that colors our emotional interpretation of the world around us.

If emotions are colors, then love is one of the artists that takes up residence in each of our minds. Artists are always much more complex than their palettes.