Defending Science - Persuasive Scientists

Who do you want to persuade?

The core question in any communication is always: Who is our target audience?
Imagine a courtroom. The arguments of the defence lawyer clash with those of the prosecutor. Are they both trying to persuade each other? Probably not; the judge is the one at stake. We call this dynamic between three parties a debate.
When it comes to persuasion, identifying the target audience can sometimes be tricky: Are we aiming to convince the person we’re speaking to, or a third party or group? If opinions vary greatly or the decision-making power doesn’t rest with the person you’re addressing, you should approach it like a debate. In this case, you directly address the person you’re speaking to, but try to influence observers or decision-makers in the background. Once you clarify the target audience, the situation becomes simpler, as you don’t need to address everyone present equally.

It’s not just rational arguments that count

Let’s examine the cornerstones of rhetoric, defined by Aristotle two and a half millennia ago: Logos, the rational arguments; Pathos, the emotional appeal; and Ethos, personal credibility.
We recognise that rational argumentation, Logos, is only one of several pillars. If you want to focus on a logical argument, you need to genuinely connect with your audience. When CERN launched the LHC particle accelerator, rumours spread that it was creating black holes. CERN responded to these concerns with straightforward, fact-based honesty, seasoned with a touch of humour.
“The LHC will not produce black holes in the cosmological sense. However, some theories propose that the creation of tiny ‘quantum’ black holes might occur. Detecting such an event would be thrilling in terms of our understanding of the Universe; and would be perfectly safe.”
The second pillar, pathos, the emotional side of arguments, can overpower the perception of your arguments. This is quite evident when nutritionists and doctors try to change habits with rational arguments. The suggestion, “Eat fewer animal products,” can provoke a storm of outrage because people feel threatened in their identity. Usually, indirect argumentation is used to avoid unnecessary emotional turmoil. “Eat more fruits and vegetables.”
The third pillar is ethos, which is the credibility of the speaker. Consider whether it is possible to establish a relationship even before the actual exchange, perhaps through a preliminary conversation or at least by explaining your motivation at the outset. Imagine you are speaking on behalf of a pharmaceutical company to an animal welfare organisation. Allow them a glimpse behind the scenes so they can see that you are making significant efforts to reduce the number of animals used in experiments and their suffering. While this won’t eliminate all objections, you will be seen as a compassionate person who doesn’t take animal lives lightly. Also, consider who is best positioned to convey the message. Who is most competent (Logos) and will find it easiest to build rapport (Ethos)?
A fourth pillar, which is often overlooked, is Kronos, or time. For instance, if you wish to ask your boss for a pay rise, it’s better not to do so when she’s stressed. Arguments are also always influenced by the prevailing political climate: If you advocate for renewable energy, you can currently be more effective by emphasising energy security rather than climate protection.
This series of articles examines the role of scientists in society. The question arises as to how to proceed when someone is entirely resistant to factual arguments. According to Aristotle, the key lies in ethos and pathos. An anti-vaxxer is unlikely to immediately book a vaccination appointment with their family doctor. If you, as a representative of the scientific worldview, are seen as credible and sincere, and can thus reduce resistance, much has already been achieved.

Embedding Arguments in Structures

In most communication scenarios, it’s easier for your audience if you start with the main message. This provides orientation and ideally sparks interest. A major exception is when you need to persuade someone who is opposed to your arguments. Let’s consider the hypothetical example of an institute director who has to announce a salary reduction. If you jump straight in, your arguments won’t be heard: “I regret to inform you that your salary will be reduced. Let me explain why we have to do this.” However, if you first explain the background, your situation and the reasons behind it will be easier to understand: “You’ve certainly heard about the nationwide budget cuts. We’ve already taken several measures to achieve savings. Unfortunately, we have no other option but to review personnel costs as well.”
To be convincing outside the academic community, you should broaden your comfort zone of fact-based communication. However, this does not mean that facts become less important, especially in your role as a chemist.

This article is the second in a series and examines the role of science in society in broad terms. We will address the tools available to scientists who communicate effectively and make a positive contribution to our society, as well as the potential pitfalls.

This article was first published in Nachrichten aus der Chemie (issue 03-2026). See here the German original.

If you´re interested in learning more about how scientists can convince others, you might want to check out our workshop, Convincing and Debating.