Supporting Claims

Writers are generally most successful with their audiences when they can skillfully and appropriately balance the three core types of appeals to support their claim. These types of appeals are traditionally referred to by their Greek names: logos (the appeal to logic), pathos (the appeal to emotion), and ethos (the appeal to authority). 

Central circle reads "Persuasion." Three circles connect out from it: 1-"Ethos / trust / authority." 2 - "Pathos / emotion / beliefs." 3 -"Logos / logic / reasoning."

Logical Appeals

Authors using logic to support their claims may include a combination of different types of evidence, which may include the following:

  • established facts
  • case studies
  • statistics
  • experiments
  • analogies and logical reasoning
  • citation of recognized experts on the issue

Authoritative Appeals

Authors using authority to support their claims may draw from a variety of techniques, which may include the following:

  • personal anecdotes
  • illustration of deep knowledge on the issue
  • citation of recognized experts on the issue
  • testimony of those involved first-hand on the issue

Emotional Appeals

Authors using emotion to support their claims have a variety of options, which may include the following:

  • personal anecdotes
  • narratives
  • impact studies
  • testimony of those involved first-hand with the issue

As you can see, there is some overlap on these lists. Different types of appeals may be used in a variety of ways.

Most logical argument essays rely on some combination these three types of supporting appeals, perhaps with one type as the primary method of support, as appropriate to the claim, but with enhancement from the other types of supporting appeals at the same time.

Application of Concepts

As you develop support for your thesis/claim, consider the type of claim and the type of support that will best convince your audience of your claim, with the understanding that you are still writing a logical argument (and not an argument based solely on emotional appeals).

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For example:

Claim of fact – Decreasing carbon dioxide emissions from car exhaust, manufacturing processes, fertilizers, and landfills, while slowing deforestation, may help slow the process of global warming.

Logical support might include:

  • Facts that show the linkage between increased carbon dioxide levels and warmer temperatures
  • Studies done showing that fuel emission laws enacted in a certain location cut down on carbon dioxide levels
  • Citation of recognized experts in the field
  • Testimony of those involved first-hand with the issue

Claim of value – Good nutrition should be taught in school rather than at home.

Logical support might include:

  • Statistics – studies done over time, showing that elementary school children who receive lessons on good nutrition maintain good eating habits into adulthood moreso than those do not receive formal lessons
  • Personal narratives
  • Citation of recognized experts in the field
  • Testimony of those involved first-hand in the issue

Claim of policy – Just as smoking ads have been banned in order to decrease viewers’ urges to engage in unhealthy behavior, soda ads should be banned for the same reason.

Logical support might include:

  • Facts showing linkage of soda consumption to increased chance of various diseases
  • Citation of recognized experts on the issue
  • Case studies
  • Statistics
  • Narratives

Another application of concepts

Claim of Fact:

Decreasing carbon dioxide emissions from car exhaust, manufacturing processes, fertilizers, and landfills, while slowing deforestation, may help slow the process of global warming.

Supporting appeal to logos:

“The planet’s average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere.5 Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010. Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year — from January through September, with the exception of June — were the warmest on record for those respective months. 6″ 

(from NASA’s website at; there’s also a very useful chart showing the increase in carbon dioxide levels )

Supporting appeal to ethos:

On the same NASA site, you can find an appeal to ethos, or authority.  At, NASA provides a graph that shows the rise in temperature and states that the graph includes “Temperature data from four international science institutions. All show rapid warming in the past few decades and that the last decade has been the warmest on record. Data sources: NASA’s Goddard Institute for Space Studies, NOAA National Climatic Data Center, Met Office Hadley Centre/Climatic Research Unit and the Japanese Meteorological Agency.”

Supporting appeal to pathos:

The following is a pathos-based appeal from the trailer for Al Gore’s documentary An Inconvenient Truth meant to convince viewers that they should do something about global warming (and, of course, watch the movie):

The Arctic is experiencing faster melting. If this [Arctic ice] were to go, sea level worldwide would go up 20 feet. . . . Here’s Manhattan. The World Trade Center Memorial would be underwater. Think of the impact of a couple hundred thousand refugees and then imagine 100 million.  . . . We have to act together to solve this global crisis. Our ability to live is what is at stake. (Gore, 2007)

Gore’s statement about the World Trade Center Memorial clearly appeals to our emotions. After all, he could have chosen countless other landmarks in the country, but he chose the site commemorating the loss of several thousand innocent civilians from an act of terrorism. We might assume, then, that his primary goal is to instill a sense of grief, fear, and outrage.

Analyze your claim (fact-value-policy) to determine the types of supporting appeals that will best prove that claim, keeping in mind that you may use appeals to logos, ethos, and pathos for any type of claim.  The type of claim may simply help you understand the type of supporting appeal you might emphasize in your essay.