Pathos ("//, "US: "//; plural: pathea; "Greek: πάθος, for ""suffering" or ""experience"; "adjectival form: 'pathetic' from παθητικός) represents an appeal to the emotions of the audience, and elicits feelings that already reside in them. Pathos is a communication technique used most often in "rhetoric (where it is considered one of the three "modes of persuasion, alongside "ethos and "logos), and in literature, film and other narrative art.
Emotional appeal can be accomplished in a multitude of ways:
In "Rhetoric, "Aristotle identifies three artistic modes of persuasion, one of which is "awakening emotion (pathos) in the audience so as to induce them to make the judgment desired." In the first chapter, he includes the way in which "men change their opinion in regard to their judgment. As such, emotions have specific causes and effects" (Book 2.1.2–3). Aristotle identifies pathos as one of the three essential modes of proof by his statement that "to understand the emotions—that is, to name them and describe them, to know their causes and the way in which they are excited (1356a24–1356a25). Aristotle posits that, alongside pathos, the speaker must also deploy good "ethos in order to establish credibility (Book 2.1.5–9).
Aristotle details what individual emotions are useful to a speaker (Book 2.2.27). In doing so, Aristotle focused on whom, toward whom, and why, stating that "[i]t is not enough to know one or even two of these points; unless we know all three, we shall be unable to arouse anger in anyone. The same is true of the other emotions." He also arranges the emotions with one another so that they may counteract one another. For example, one would pair sadness with happiness (Book 2.1.9).
With this understanding, Aristotle argues for the "rhetor to understand the entire situation of goals and audiences to decide which specific emotion the speaker would exhibit or call upon in order to persuade the audience. Aristotle’s theory of pathos has three main foci: the frame of mind the audience is in, the variation of emotion between people, and the influence the rhetor has on the emotions of the audience. Aristotle classifies the third of this trio as the ultimate goal of pathos. Similarly, Aristotle outlines the individual importance of persuasive emotions, as well as the combined effectiveness of these emotions on the audience. Moreover, Aristotle pointedly discusses pleasure and pain in relation to the reactions these two emotions cause in an audience member. According to Aristotle, emotions vary from person to person. Therefore, he stresses the importance of understanding specific social situations in order to successfully utilize pathos as a mode of persuasion.
Aristotle identifies the introduction and the conclusion as the two most important places for an emotional appeal in any persuasive argument.
Pathos has its hand in politics as well, primarily in speech and how to persuade the audience. Mshvenieradze states that "Pathos is directly linked with an audience. Audience is a collective subject of speakers on which an orator tries to impact by own argumentation."  Similarly to how Aristotle discusses how to effectively utilize pathos in rhetoric, the way in which one appeals to the reader is similar in appealing to an audience of voters. In the case of politics and politicians, it is primarily more in argumentative writing and speaking. In Book II of Aristotle's writing's in Rhetoric, in essence knowing people's emotions helps to enable one to act with words versus writing alone, to earn another's credibility and faith. 
As Aristotle's teachings expanded, many other groups of thinkers would go on to adopt different variations of political usage with the elements of pathos involved, which includes groups such as the Epicureans and Stoics.
Scholars have discussed the different interpretations of Aristotle’s views of "rhetoric and his philosophy. Some believe that it is actually a myth, that Aristotle invented it entirely.["clarification needed] In the second chapter of "Rhetoric, Aristotle's view on pathos changes from the use in discourse to the understanding of emotions and their effects. William Fortenbaugh pointed out that for the "Sophist "Gorgias, "Being overcome with emotion is analogous to rape." Aristotle opposed this view and created a systematic approach to pathos. Fortenbaugh argues that Aristotle's systematic approach to emotional appeals "depends upon correctly understanding the nature of individual emotions, upon knowing the conditions favorable to, the objects of, and the grounds for individual emotions".
Modern philosophers were typically more skeptical of the use of emotions in communication, with political theorists such as "John Locke hoping to extract emotion from reasoned communication entirely. "George Campbell presents another view unlike the common systematic approach of Aristotle. Campbell explored whether appeals to emotion or passions would be "an unfair method of persuasion," identifying seven circumstances to judge emotions: probability, plausibility, importance, proximity in time, connection of place, relations to the persons concerned, and interest in the consequences.
The 84 BC "Rhetorica ad Herennium book of an unknown author theorizes that the conclusion is the most important place in a persuasive argument to consider emotions such as mercy or hatred, depending on the nature of the persuasion. The "appeal to pity", as it is classified in Rhetorica ad Herennium, is a means to conclude by reiterating the major premise of the work and tying while incorporating an emotional sentiment. The author suggests ways in which to appeal to the pity of the audience: "We shall stir pity in our hearers by recalling vicissitudes of future; by comparing the prosperity we once enjoyed with our present adversity; by entreating those whose pity we seek to win, and by submitting ourselves to their mercy." Additionally, the text impresses the importance of invoking kindness, humanity and sympathy upon the hearer. Finally, the author suggests that the appeal to pity be brief for "nothing dries more quickly than a tear."
Aristotle's teachings would go on to influence many influential groups of thinkers. One such group of thinkers, the Epicureans who practiced Epicureanism, interpreted and placed pathos in much more colloquial means and situations. The group would place pathos in pleasure, and study it in almost every facet in regards to pleasure, analyzing emotional specificity that an individual may feel or may need to undergo to appreciate said pathos. 
The concept of emotional appeal existed in rhetoric long before Aristotle’s Rhetoric. "George A. Kennedy, a well-respected, modern-day scholar, identifies the appeal to emotions in the newly formed democratic court system before 400 BC in his book, The Art of Persuasion in Greece. "Gorgias, a Sophist who preceded Aristotle, was interested in the orator’s emotional appeal as well. Gorgias believed the orator was able to capture and lead the audience in any direction they pleased through the use of emotional appeal. In the Encomium of Helen, Gorgias states that a soul can feel a particular sentiment on account of words such as sorrow and pity. Certain words act as "bringers-on of pleasure and takers-off of pain. Furthermore, Gorgias equates emotional persuasion to the sensation of being overtaken by a drug: "[f]or just as different drug draw off different humors from the body, and some put an end to disease and other to life, so too of discourses: some give pain, others delight, others terrify, others rouse the hearers to courage, and yet others by a certain vile persuasion drug and trick to soul."
"Plato also discussed emotional appeal in rhetoric. Plato preceded Aristotle and therefore laid the groundwork, as did other Sophists, for Aristotle to theorize the concept of pathos. In his dialogue "Gorgias, Plato discusses pleasure versus pain in the realm of pathos though in a fictional conversation between Gorgias and Socrates. The dialogue between several ancient rhetors that Plato created centers around the value of rhetoric, and the men incorporate aspects of pathos in their responses. Gorgias discredits pathos and instead promotes the use of "ethos in persuasion. In another of Plato’s texts, "Phaedrus, his discussion of emotions is more pointed; however, he still does not outline exactly how emotions manipulate an audience. Plato discusses the danger of emotions in oratory. He argues that emotional appeal in rhetoric should be used as the means to an end and not the point of the discussion.
"George Campbell, a contributor to the Scottish Enlightenment, was one of the first rhetoricians to incorporate scientific evidence into his theory of emotional appeal. Campbell relied heavily on a book written by physician "David Hartley, entitled "Observations on Man. The book synthesized emotions and neurology and introduced the concept that action is a result of impression. Hartley determined that emotions drive people to react to appeals based on circumstance but also passions made up of cognitive impulses. Campbell argues that belief and persuasion depend heavily on the force of an emotional appeal. Furthermore, Campbell introduced the importance of the audience’s imagination and will on emotional persuasion that is equally as important as basic understanding of an argument. Campbell, by drawing on the theories of rhetoricians before him, drew up a contemporary view of pathos that incorporates the psychological aspect of emotional appeal.
An orator’s reliance on emotional appeal is evident in modern-day speechmaking, but in some schools of thought this is seen primarily as psychological versus emotional appeal.["clarification needed]
Speech is one of the primary places where one sees the application of pathos. Pathos is in essence the driving force behind an argument, to hit the emotional pangs that allow the audience to relate to the speaker.