It’s hard to believe yet true—the secrets to long-lasting love come from two unlikely and not particularly romantic sources. One is the teachings of the ancient Greek philosopher Aristotle…and the other is modern science.

Want your love to last and last? They can tell you how.

Aristotle believed that while friendships could be useful (think business associates) or pleasurable (think tennis partners), the most lasting friendships are among people who see goodness in each other and are inspired by it to become better people themselves.

Now apply this to romantic relationships. The partners in the most sustainable ones are focused on seeing and loving the good in the other person, not on themselves or what they can get out of the relationship. In other words, focusing on the other person benefits the relationship much more than focusing on yourself does. Ultimately, that effect on the relationship rebounds and helps you just as much—so it’s all good. You just have to stop focusing so much on Number One to make it happen.

Where does modern science come in? It shows you how to put the philosophy into practice. Positive psychology researchers have learned a great deal about how using positive emotions can help people and relationships flourish. By tapping into this knowledge, you can recognize and nurture what’s right in your relationship instead of dwelling on what’s wrong with it or, worse still, on each other’s shortcomings, a trap couples often fall into. Here’s how…

Create happiness. Don’t wait for happiness to happen—it’s not like crabgrass that shows up on its own. While some people might seem naturally happy, that feeling could come from making time for activities that bring them happiness. So, for example, schedule daily couple’s time for simple pleasures that you both enjoy—it doesn’t have to be any more complicated than taking a walk or doing a crossword puzzle together.

Show your appreciation for each other. Many relationships fall apart not because of big problems but because of small, everyday issues, such as taking each other for granted. Don’t wait for the big, momentous occasions, such as your anniversary, to celebrate each other. Even if you have a hectic schedule, you can slow down long enough to savor and acknowledge little moments with your partner—maybe he/she gathered a wildflower bouquet or made an impressive new dish for you for dinner.

Identify and understand your strengths and those of your partner. Couples who see each other through a lens of respective strengths experience a deeper connection—and, by the way, greater sexual satisfaction. Positive psychology researchers have identified 24 character strengths that have been valued across time and culture—qualities such as kindness, creativity, love of learning and zest. The good news is that we all have strengths, just in different configurations. So do this: Take the free VIA survey (registration is required) to see what it says are your top five strengths, commonly referred to as your “signature strengths,” and ask your partner to do the same. Once you’ve each identified your strengths, begin having “strengths conversations” with each other, sharing what it feels like to have these specific strengths. This may be an eye-opener for both of you.

Find ways to mesh each other’s strengths and likes. You two are different from each other, right? That’s great—use it. Consciously plan experiences together that will appeal to both of you. Say, for instance, that one of you is particularly creative and the other has an unusually strong love of learning. What might you do together? How about a visit to a nearby historic site to photograph the unusual historic architecture and to learn more about the history of the area? There are many things you can do together that will satisfy both of your likes—even those likes that aren’t shared.

Reframe your expectations of the perfect relationship. Many people get caught up in the idea of needing a perfect “soul mate.” The notion that there’s one person who was created just for you is certainly romantic, but it may not be at all realistic. Instead, look for your partner to complement, not complete, you. Focus on loving the good in each other, supporting each other’s desire to grow, and in turn each becoming inspired to become a better self. Your love will last.