Moral arguments are often infuriating; you’re left sitting there, wondering how on earth your opponent can believe in what they’re saying. Rooted in this is not an information imbalance – where one person is misinformed and shifts their position as they get to know more about a topic – but rather our innate moral reasoning, based upon six foundations of morality. These six foundations are like tastebuds – some people prefer sweets, whilst others prefer chocolate. Appealing to the foundations people care about most is the key to winning moral arguments.
So, what are the six foundations of morality? The first is the harm/care principle. This is the idea that we feel compassion towards others – especially the weak and vulnerable – and look very unfavourably towards those who we perceive to cause harm. It is rooted in the fact that we are mammals, and so are full of neural and hormonal programming that drives this sense of compassion and bonding we feel towards others1.
The second moral foundation is fairness/cheating – everybody should be treated equally. It stems from the evolutionary process of reciprocal altruism: we help others at a cost, in anticipation that the benefactor will return this act of selflessness2.
The third foundation is loyalty. This stems from our origins as tribal creatures, but we have also been the only species that have formed large groups, such as nations. As a result, we see betrayal as a great negative.
Another foundation is authority. Humans have had a long history of social hierarchy, and consequently, we see those who undermine legitimate authority and respect for traditions in a negative light as well.
The fifth foundation is sanctity – the idea that the body is pure, and should be protected from contamination. This moral foundation can be invoked whilst talking about a range of things – the environment, traditions, or religion, to name but a few.
The last foundation is liberty/oppression.3 This foundation is about the resentment people feel towards those who attempt to restrict their liberty.
These six are arguably the biggest key to understanding how to persuade people. When forming moral arguments, people lean on each of these foundations in different amounts. However, what Jonathan Haidt and others found is that the differences in how we weigh each moral foundation correlates with our politics (Figure 1).4 They found that those on the left lean more on the foundations of fairness and care, whilst those on the right prioritise other foundations, that liberals rarely even consider5.
The differences in humanity’s moral framework can be explained by the Social Cognition Theory. This suggests that a person’s way of thinking ultimately stems from observing their environment and others7. Ultimately, for the six moral foundations, different perceptions of threat are the key. Those who are more sensitive to danger and ambiguity tend to be conservatives, as they place more emphasis on loyalty, sanctity and authority. Those who are more tolerant of novelty and complexity are largely liberals, emphasising fairness and care. As a result, these moral variations correlate well with the political spectrum.
How does this help win moral arguments? Firstly, it is important to note that not every argument will be based on these foundations. Further, persuasion depends on understanding your opponent’s background. Moral arguments, by definition, occur between those who believe different things, and so to be more convincing, it is crucial to appeal to their moral foundations, not yours.
For example, when Greta Thunberg talks about climate change, she says, ‘People are suffering. People are dying.’8 This invokes the moral principle of harm/care – that we should do something about climate change to help protect others. As a result, she is largely appealing to those who already support her views about climate change – liberals9 – and is less persuading to conservatives who disagree with her.
Now, if we look at President Obama talking about the Yosemite Valley in California, he doesn’t invoke the foundations of fairness or care, but rather sanctity – climate change is threatening nature’s purity. He talks about how ‘there’s something sacred about this place’ and ‘protecting our sacred spaces’.10 This is wildly different to how Greta Thunberg and most liberals talk about climate change – he’s appealing to those who disagree with him.
As a result, President Obama’s message is better at winning the moral argument of action on climate change. The President and Greta Thunberg both share the same view, and voice the same beliefs, but the way Obama does it is more persuasive to his opponents. In this way, the moral foundations are an insight into how to win arguments – by considering why the other side believes what they do, you can understand and appeal to them better.
To summarise, the six moral foundations of care, fairness, authority, loyalty, sanctity and freedom are the key to understanding why different moral arguments appeal to different people. Once you have done this, it is much easier to create a moral argument that is more appealing to those who disagree with you, helping you win over the opposing side.
- TED-Ed. “The Moral Roots of Liberals and Conservatives – Jonathan Haidt.” 31 December, 2012.
2 Dobolyi, David. “Moral Foundations Theory | Moralfoundations.org.” September 2024.
3 Haidt, Jonathan. The Righteous Mind: Why Good People Are Divided by Politics and Religion. 2012.
4 Graham, Jesse, Brian A. Nosek, Jonathan Haidt, Ravi Iyer, Spassena Koleva, and Peter H. Ditto. “Mapping the Moral Domain.” 2011.
5 Haidt, Jonathan, and Jesse Graham. “When Morality Opposes Justice: Conservatives Have Moral Intuitions That Liberals May Not Recognize.” 2007.
6 Liphardt, Jan. “Moral Foundations Primer.” 2021.
7 Nickerson, Charlotte. “Albert Bandura’s Social Cognitive Theory.” 2025.
8 NPR. “Transcript: Greta Thunberg’s Speech at the U.N. Climate Action Summit.” September 23, 2019.
9 Blazina, Carrie. “More Americans See Climate Change as a Priority, but Democrats Are Much More Concerned than Republicans.” February 28, 2020.
10 Obama White House. “Remarks by the President at Sentinel Bridge.” June 18, 2016.
