Every year, new books on leadership come out and the business world hungrily buys, reads and digests them. Book summary companies provide compressed descriptions for busy executives, professional service providers and entrepreneurs.

It is estimated that between 1986 and 1996, 17,800 management journal articles were written about leadership.

In my practice, coaching lawyers and executives, I read many books, articles and blogs. They help me tend and grow my own business and when I find something useful, I share it with clients, sometimes ­forwarding an article or recommending a book during a coaching conversation.

Leadership theory has seen innovation stemming from increased knowledge about biology, psychology, emotional intelligence and behavioral science. Authors like Daniel Pink, the Heath Brothers, and Dr. Dan Siegel are riding the crest of increased interest in what motivates us and ­others, along with mindfulness as a method of ­self-management and stress relief. But there is wisdom to be found in older tomes, too.

Recently, I re-read an old chestnut—”How to Win Friends and Influence People” by Dale Carnegie – originally published in 1937. Eighty years later it is still highly relevant when it comes to improving confidence, relationships and leadership and full of valuable, practical advice.

Carnegie began teaching public speaking in 1911 when he was unemployed, broke and living at a YMCA. By 1935, he was lecturing to crowds of 2,500.

Besides health, Carnegie found, people are most interested in developing skill in human relationships and he realized that his training in public speaking had done more to give him confidence, courage, poise and the ability to meet and deal with people in business than all of his college courses combined. “Dealing with people is probably the biggest problem you face, especially if you are in business,” he wrote. Does that sound familiar?

The book is divided into sections: “Fundamental Techniques in Handling People;” “Six Ways to Make People Like You;” “How to Win People to Your Way of Thinking;” and “Be a Leader: How to Change People Without Giving Offence or Arousing Resentment.” Each section offers principles designed to effectuate the stated result.

Although some tips are designed to win people over through compliments and ­flattery, his consistent message is sincerity. Rather than an empty overture, he exhorts the reader to find things to be ­authentically enthusiastic about in the other person. Carnegie returns to this theme throughout: “The principles taught here will work only when they come from the heart. I am not advocating a bag of tricks. I am talking about a new way of life.

The book is focused on influence—how to get what you want from others—and Carnegie starts with the premise that there is only one way: making people want to do it by giving them what they want. And what do they want most? To feel important. Feeding that desire is a major component of Carnegie’s philosophy and method. But always, he insists, be genuine about it.

On getting people to like you, he writes “you can make more friends in two months by becoming ­genuinely interested in other people than you can in two years by ­trying to get other people interested in you.” Quoting Alfred Adler, he writes “it is the individual who is not interested in his fellow men who has the greatest difficulties in life and provides the greatest injury to others.”

I went to a continuing legal education seminar years ago and seated right next to me was a law school classmate of mine. There was little chance he wouldn’t ­recognize me, but he never turned his gaze in my direction, nor did he look to his other side. He spent the entire seminar with eyes trained straight ahead, clearly not looking to connect with others. It became a game on my end. If I looked at him, would he look back? Would he notice others? It seemed a shame, a lost opportunity because professional seminars are a great place to network. And, networking is about making new friends and tending to current ones. My classmate would never be a rainmaker because he’s not interested in people. As Carnegie writes, “you must have a good time meeting people if you expect them to have a good time meeting you.”

He urges the reader to be animated, ­upbeat and to smile, even when making telephone calls because “the effect of a smile is powerful, even when it is unseen.” It can also change your own attitude according to psychologist William James, who Carnegie quotes: “Action seems to follow feeling, but really action and feeling go together, and by regulating the action, which is under the more direct control of the will, we can indirectly regulate the feeling, which is not.” In recent years, the work of Amy Cuddy and others further validates the point that body language can influence and improve self-assurance and performance.

Carnegie is not suggesting that we paste phony smiles on our faces. Improving your mental attitude so you can have an impact on others is his main thrust. He writes: “Everyone in the world is seeking ­happiness, and there is one sure way to find it. That is by controlling your thoughts. Happiness doesn’t depend on outward conditions. It depends on inner conditions. It isn’t what you have or who you are or where you are or what you are doing that makes you happy or unhappy. It is what you think about it.”

My coaching clients are often reluctant to network and market. Chief among the reasons is not knowing what to talk about with new people. Carnegie offers solutions. “If you aspire to be a good conversationalist, be an attentive listener. To be ­interesting, be interested. Ask questions that other persons will enjoy answering. Encourage them to talk about themselves and their accomplishments.”

Carnegie urges us to develop the habit of seeing things through the eyes of others. Modern writers would call it empathy. “If, as a result of reading this book, you get only one thing—an increased tendency to think always in terms of the other person’s point of view, and see things from that person’s angle as well as your own—if you get only that one thing from this book, it may easily prove to be one of the stepping stones of your career.”

I have a client preparing to go on ­paternity leave and getting static from his boss about it. He was irritated and close to giving the boss a piece of his mind. I asked him to think about it from the boss’ point of view. What is he worried about? What could you do to calm his anxiety about your absence? What does he need? While the boss was ­behaving badly, there were options available to my client to resolve, rather than escalate.

Carnegie is a big fan of appreciation. Quoting psychologist Jess Lair: “Praise is like sunlight to the warm human spirit; we cannot flower and grow without it. And yet, while most of us are only too ready to apply to others the cold wind of criticism, we are somehow reluctant to give our fellow the warm sunshine of praise.”

I was at the gym recently and a fellow member told me he was impressed by how hard I was working and his kind words stayed with me the rest of the day. He didn’t want anything from me. Just passing along a little sunshine. Try doing that and see how it improves your day to make another person blossom from your warmth.

The book is replete with stories and ­lessons as applicable today as in Carnegie’s day because humans are still the same. Try some tips and watch your relationships, ­influence and business improve.

Reprinted with permission from the August 28, 2017 edition of “The Legal Intelligencer” © 2017 ALM Media Properties, LLC. All rights reserved. Further duplication without permission is prohibited. For information, contact 877-257-3382, reprints@alm.com or visit www.almreprints.com.