How to Know When You Love Someone

The word "love" can have a variety of related but distinct meanings in different contexts. Many other languages use multiple words to express some of the different concepts that in English are denoted as "love"; one example is the plurality of Greek concepts for "love" (agape, eros, philia, storge).[9] Cultural differences in conceptualizing love make it difficult to establish a universal definition.[10]

Although the nature or essence of love is a subject of frequent debate, different aspects of the word can be clarified by determining what is not love (antonyms of "love"). Love, as a general expression of positive sentiment (a stronger form of like), is commonly contrasted with hate (or neutral apathy). As a less sexual and more emotionally intimate form of romantic attachment, love is commonly contrasted with lust. As an interpersonal relationship with romantic overtones, love is sometimes contrasted with friendship, although the word love is often applied to close friendships or platonic love. (Further possible ambiguities come with usages like "girlfriend", "boyfriend" and "just good friends".)
Abstractly discussed, love usually refers to a feeling one person experiences for another person. Love often involves caring for, or identifying with, a person or thing (cf. vulnerability and care theory of love), including oneself (cf. narcissism). In addition to cross-cultural differences in understanding love, ideas about love have also changed greatly over time. Some historians date modern conceptions of romantic love to courtly Europe during or after the Middle Ages, although the prior existence of romantic attachments is attested by ancient love poetry.[11]

The complex and abstract nature[clarification needed] of love often reduces its discourse to a thought-terminating cliché. Several common proverbs regard love, from Virgil's "Love conquers all" to The Beatles' "All You Need Is Love". St. Thomas Aquinas, following Aristotle, defines love as "to will the good of another."[12][13] Bertrand Russell describes love as a condition of[clarification needed] "absolute value," as opposed to relative value.[14] Philosopher Gottfried Leibniz said that love is "to be delighted by the happiness of another."[15] Meher Baba stated that in love there is a "feeling of unity" and an "active appreciation of the intrinsic worth of the object of love."[16] Biologist Jeremy Griffith defines love as "unconditional selflessness".[17]
Is Love Influenced By Biology or Culture?
Some researchers suggest that love is a basic human emotion just like happiness or anger, while others believe that it is a cultural phenomenon that arises partly due to social pressures and expectations.

Research has found that romantic love exists in all cultures, which suggests that love has a strong biological component. It is a part of human nature to seek out and find love. However, culture can significantly affect how individuals think about, experience, and display romantic love
Is Love an Emotion?
Psychologists, sociologists, and researchers disagree somewhat on the characterization of love. Many say it's not an emotion in the way we typically understand them, but an essential physiological drive. Psychologist and biologist Enrique Burunat says, "Love is a physiological motivation such as hunger, thirst, sleep, and sex drive."5 Conversely, the American Psychological Association defines it as "a complex emotion."6
American Psychological Association. APA Dictionary of Psychology.

Still others draw a distinction between primary and secondary emotions and put love in the latter category, maintaining that it derives from a mix of primary emotions.