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A possibly true anecdote from Ancient Greece tells of Diogenes the Cynic bursting into Plato's school holding a plucked chicken and saying, "Behold, Plato's man!" in response to the famous philosopher's definition of man being a featherless biped. One of Plato's students, Aristotle, was more specific when he stated that reason, or logic, was the characteristic that sets humans apart from other animals.1 Logos, the use of logic to support an argument, could thus be argued to be the most important of all the classical appeals.

Logos A Portrait of Aristotle StudySmarter

A portrait of Aristotle, pixabay.

Logos Definition

Aristotle defined three classical appeals in rhetoric to be aware of–logos (logic), pathos (emotion), and ethos (character). These rhetorical appeals are present in all writing, depending on the genre and subject matter. Logos refers to the use of rationality or reason and appeals to the reader's sense of logic. When a writer or speaker cites a statistic, scientific study, or fact, uses if-then statements, or makes comparisons, they use logos.

There are different modes of reasoning, but the two most common are:

  • Inductive: gathering specific examples and drawing a general conclusion from them. Inductive reasoning is the kind of reasoning used in the scientific method. Experiments are run with similar control factors, variables, and results. From there, it's possible to draw a conclusion about the nature of the experiments that explains widespread phenomena. A person using inductive reasoning in a speech or paper could give three examples of scientific experiments that concluded the same results to show that the hypothesis of the experiments was true or false.
  • Deductive: coming to a logical conclusion based on valid premises. When you use deductive reasoning, you lay out generalized premises that are true and draw a specific conclusion. Deductive reasoning is used in mathematics, but other applications include creating scientific hypotheses and ethical and political arguments. Syllogisms are a type of deductive reasoning where a conclusion is drawn based on two premises. The conclusion is constructed from a word included in each of the premises, and the premises both share a word that's not part of the conclusion.

A famous syllogism:

1) All men are mortal.

2) Socrates was a man.

Therefore Socrates is mortal.

People use inductive reasoning in everyday life to make educated guesses about the world around them. For example, they leave the house at a specific time to arrive at a destination without being late or predict someone's future behavior based on what they've done in the past. Can you think of instances where you've used inductive reasoning?

Logos, Ethos, and Pathos Rhetorical Analysis

When examining an argument, pathos refers to an appeal to emotion, ethos is the voice of authority, and logos is how logical the argument is. In a rhetorical analysis, pathos is judged by the reader's beliefs and emotional response. Ethos represents the author's credibility. Logos examines the words in the text and looks at their validity. Unless it is a scientific, mathematical, or philosophical argument, the argument's propositions, axioms, and conclusions will not be explicitly laid out. It's up to the reader to ignore the author's appeals to pathos and ethos to identify the validity of the author's argument through their use of logos.

Logos Relationship between logos, ethos, and pathos StudySmarter

An illustration of the relationship between logos, ethos, and pathos, StudySmarter Originals

Logos and Rhetoric

Whenever a writer or speaker gives reasons, they are using logos. They use logos whenever they cite a source, a scientific study, or a statistic. The first thing one should do is try to understand the argument of a writer or speaker. Then one can see how a fact, statistic, or citation fits into and supports that argument. Analyze the argument's reasoning to see whether or not it is valid and sound.

When looking at a writer or speaker's sources, it's essential to see whether or not they are credible or believable. It's also important to keep in mind the audience. A less educated audience or an audience that does not have expertise in a particular field is more apt to believe the sources cited. Regardless, if a source is not credible or trustworthy, one can analyze how this negatively affects the argument.

The CRAAP Method helps judge whether a source is reliable or not:

Currency: Does the source reflect the most recent information about the subject?

Relevance: Does the source support the argument?

Authority: Is the source knowledgeable about the subject?

Accuracy: Can the source's information be cross-checked with other sources?

Purpose: Why was the source written?

Logos Examples

Logos are used in many different areas, but mainly in science because of the importance of the scientific method. It is also widely used in politics to persuade voters and other politicians that there is a problem that a particular policy can address. Logos is also important in literature and history as well.

Logos Example in a Rhetorical Analysis Essay

In a rhetorical analysis of Jessica Grose's "Cleaning: The Final Feminist Frontier," the author of the essay, Harriet Clark, writes:

Grose uses strong appeals to logos, with many facts and statistics and logical progressions of ideas. She points out facts about her marriage and the distribution of household chores: 'My husband and I both work. We split midnight baby feedings...but ...he will admit that he’s never cleaned the bathroom, that I do the dishes nine times out of ten, and that he barely knows how the washer and dryer work in the apartment we’ve lived in for over eight months.' These facts introduce and support the idea that Grose does more household chores than her husband. Grose continues with many statistics: [A]bout 55 percent of American mothers employed full time do some housework on an average day, while only 18 percent of employed fathers do.... [W]orking women with children are still doing a week and a half more of “second shift” work each year than their male partners.... Even in the famously gender-neutral Sweden, women do 45 minutes more housework a day than their male partners. These statistics are a few of many that logically support her claim that it is a substantial and real problem that men do not do their fair share of the chores. The details and numbers build an appeal to logos and impress upon the reader that this is a problem worth discussing."2

Clark talks about an appeal to logos, and she makes sure to examine how Grose uses facts and statistics that support her argument. Clark's analysis argues that because Grose cites facts and sources, its logos appeal is persuasive.

Whenever crafting a persuasive argument, an author or speaker must put forth a logical argument. Whether the argument is true or not is not necessarily relevant because presenting an argument with supporting evidence is enough to lend credibility to an author or speaker. This demonstrates the relationship between logos and ethos. The use of logos can create a sense of ethos by making it seem like the author has prepared themselves and researched their particular issue.

Logos can be incorporated into an argument by laying forth theories, citing evidence to support those theories, and drawing rational conclusions from propositions. This requires a certain amount of thinking as well as significant amounts of research. Sometimes it even includes the study of data or experimentation. The most important thing is that the knowledge acquired is presented in a coherent and easy-to-understand way.

Political Examples of Logos

An example of logos being used in politics can be found in a National Review article where Kathryn Lopez argues that Ukraine is a country where there is freedom of religion. Lopez writes:

Really, there is unity in Ukraine. There’s toleration. Ukraine today has a Jewish president, and in the summer and fall of 2019, both the president and the prime minister were Jewish — the only country besides Israel where the head of state and head of government were Jewish was Ukraine. Ukraine has Russian schools, the Russian Orthodox Church has thousands of parishes there. By comparison, there are hundreds of thousands of Ukrainian Greek Catholics in Russia, and they do not have a single legally registered parish. Ukrainians in Russia, who number between four and six million, do not have a single Ukrainian language school."3

To bolster her argument, Lopez cites facts. She's arguing against the notion that Ukraine subordinates the Orthodox Church to the government or vice versa. She mentions how Ukraine has a Jewish president, and Russian Orthodox parishes, while Russia doesn't allow religions or schools not authorized by the state.

Lopez's logos is compelling because it presents two similar nations but gives evidence to show how different they are. Comparatively, based on the facts that Lopez presents, Ukraine is a nation that allows for the exercise of religious freedom and the freedom to speak any language. Despite similar demographics, there's no evidence that they have these freedoms in Russia.

The end goal of the argument is to show that Ukraine is a similar country to the United States or other Western European nations and to smear the Russian state as totalitarian. This in itself appeals to the sympathies of Americans and Western Europeans. This shows the interplay between logos and pathos because although she has rational reasons, the implications of her facts tell the reader that Ukrainians are like Americans. Since people often feel compassion for those similar to them, they would side with the Ukrainian government and not the Russian.

Literary Examples of Logos

And here's an example of logos from one of the most famous novels - Crime and Punishment.

Crime and Punishment (1866)

In Fyodor Dostoevsky's novel Crime and Punishment (1866), the main character Raskolnikov hypothesizes that there are two types of men: extraordinary men and ordinary men. Extraordinary men are not bound by moral laws and can transcend them to improve society. Philosophers like Hegel and Nietzsche had theorized this. Raskolnikov believes himself to be an extraordinary man and tests this by murdering a greedy old lady who cheats people out of their money and doesn't use it or give it to those in need. His theory is laid out as such:

  1. There are two types of men–extraordinary and ordinary.
  2. Extraordinary men are not bound to moral laws like ordinary men.
  3. Since moral laws do not bind them, an extraordinary man may commit murder.
  4. Raskolnikov is an extraordinary man.

Therefore, it is permissible for Raskolnikov to commit murder.

Is Raskolnikov using inductive or deductive reasoning?

Dostoevsky's argument is highly effective because it gives Raskolnikov every possible justification for murder and even provides a full-fledged theory. Moreover, the statement, a central theme of the book, never receives a logical rebuttal.

Emotionally, most readers are against Raskolnikov's theory. They have been taught murder is wrong from a young age, no matter the situation. Yet readers have trouble trying to compose a counterargument to Raskolnikov's argument. In fact, it is repeated throughout the book, and the audience tends to accept this argument as valid. In addition to the argument, the audience feels like Raskolnikov is justified because of the horrible conditions he is living in. It also helps that his victim is a menace to the rest of society, and Raskolnikov has shown bravery and generosity to the rest of the community.

Dostoevsky intentionally made his character as formidable as possible because it was, in fact, a theory he was critiquing. The purpose of the logos used here is to give Raskolnikov as much credibility as possible. Dostoevsky is known for making his opponent's argument magnificent, and he does so because it enabled him to fully explore the consequences of another person's actions.

Despite Raskolnikov's flawless logic (at least in his eyes), he still descends into madness because of the murder. The adverse reaction stems from an interplay of logos, ethos, and pathos, where logically, an idea is sound, but ethically and emotionally, it is clearly immoral. Dostoevsky smartly shows how the three appeals must work together; relying on one alone leads to unsound arguments.

Logic An artist's rendition of thinking StudySmarterAn Artist's Rendition of Thinking, Pixabay

Logos - Key takeaways

  • Logos is the persuasive appeal to reason
  • The two most common ways of reasoning are inductive and deductive reasoning
  • A rhetorical analysis essay analyzes the effectiveness of logos, pathos, and ethos.
  • The analysis of logos means examining facts, sources, and the argument of a writer or speaker

1 Keil, Geert, and Nora Kreft, Eds. Aristotle's Anthropology. 2019

2 Clark, Harriet. 'Rhetorical Analysis Essay Sample | PDF.' 13 Feb. 2015.

3 Lopez, K. J. 'Fifteen Things That Caught My Eye Today: Religious Freedom in Ukraine, Chief Justice Roberts & Roe & More.' National Review. 7 March 2022.


Logos means the rationality or logic of an argument. It is important in speeches because it is what the speaker is trying to persuade the audience to believe.

You can identify the logos in a speech by examining the claims made by a speaker and the evidence for their claims.

Yes, logos is the rhetorical device that persuades through logic. Ethos persuades by authority. And pathos persuades through emotions.

Persuasive writing is a piece written with the intent to change the hearts and minds of audiences.

Inductive reasoning, deductive reasoning, statistics, facts, scientific studies, and citation of reliable sources.

Final Logos Quiz


What is logos?

Show answer


The persuasive appeal to logic.

Show question


What is inductive reasoning?

Show answer


Reasoning that takes similar anecdotes and facts and draws general conclusions from them

Show question


What is deductive reasoning?

Show answer


Reasoning that takes agreed upon general propositions and draws conclusions from them

Show question


What kind of reasoning does the scientific method use?

Show answer


Inductive Reasoning

Show question


What kind of reasoning does math use?

Show answer


Deductive Reasoning

Show question


What do speakers tend to use as support for their claims?

Show answer


Citation of facts, statistics and scientific studies

Show question


Who developed the syllogism?

Show answer



Show question


If logos is used in an argument, does it mean that the argument is true?

Show answer


Yes, always makes an argument true

Show question


How does Shakespeare's character Iago use logos?

Show answer


He tells Othello the facts that Desdemona is willing to hide relationship from her father, so she will do the same to you.

Show question


What Russian novelist was known for his use of logos to bolster his opponents arguments?

Show answer


Fyodor Dostoevsky

Show question


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