The time-tested axiom from Dale Carnegie that you can't win an argument, is true. "If you lose it, you lose it; and if you win it, you lose it," the author writes, because people will only hold onto their belief even stronger. But the art of persuasion is something entirely different.

Persuasion is the art of appealing to someone's logic or emotional capacity, not proving them wrong but opening their mind to something new or different.

Lisa Lai, who is a leadership adviser, consultant, and coach, writes in the Harvard Business Review about the best ways to persuade someone. She says instead of trying to win over both hearts and minds, you should pick one or the other. In other words, if you're not naturally charismatic and persuasive, don't go for the heart.

"Trying to leverage both emotion and logic can actually make us less influential if we don't have a plan," she writes.

Below find out when to leverage the heart and when to tap into one's logic.

When to win over the heart.

Winning over someone's heart starts with appealing to their emotions. Lai says you should focus on emotional connections when you're trying to:

  • pique someone's interest with a new idea
  • gain support for a decision that's already been made
  • boost someone's commitment
  • connect with creative or design-focused employees
  • lead employees through conflict

This is when you need to get personal and hook the other party with vivid language of a personal story or experience, Lai writes. Big changes or reorganizations fill employees with fear and discomfort, so you need to address their fears and make it clear what they will gain personally by sticking to your idea or vision. The key is to keep it personal--focus on why they should buy in as individuals.

"I've found that the most effective way to win others' hearts is to share why your idea is important and why now is the time to act, and then to highlight how it benefits the individual, the business, your clients, your partners, or the broader environment. Transparency and authenticity drive success here," Lai writes.

When to win over the mind.

When it's time to win over minds, you need to be concise and logical and articulate an analytical position is coherent. You should use logic when you're trying to:

  • change a project's direction
  • change an important decision
  • help a team see clearly when overwhelmed with data
  • address technical problems
  • advocate for your perspective when talking with other executives

Appealing to one's logic does not mean you're proving someone wrong. You should craft a simple, but highly rational message--give reasons based in fact and analysis of why one choice or perspective is pragmatic. "Provide proof to support your position in the form of data, research, expert opinions, and analysis. Discuss benefits in very tangible ways," Lai writes. Your message should be a solution to the problem.

"To win minds, you have to do your homework. Often you have just one chance to influence others. Put yourself in their position and do the work to prepare. If possible, you'll also want to relate your proposal to what matters personally using the tactics outlined in the section on winning hearts," she writes.

But, Lai warns that if your message is a mix of logic and emotion, it can make you less convincing. She suggests tailoring your message to how your audience views the world. You won't win over a CFO with emotion, just like you won't win over angry customers with logic (at least until their ire dissipates.) "Identify your strongest position based on the circumstances," she says, and craft your persuasive message to what they need to hear to come over to your side.