Introduction

In his essay “Letter from Birmingham Jail,” Martin Luther King Jr. credits many people for influencing his thinking. A few of the people he mentions are Socrates, St. Thomas Aquinas, Paul Tillich, Martin Buber, St. Augustine, Jesus, Martin Luther, John Bunyan, Thomas Jefferson, and the Apostle Paul. He is not writing a research report about these people. In fact, he doesn’t have to mention them at all because of how old and foundational these ideas are. But he brings them into his writing because they have ideas that support the ideas he is expressing, and their ideas helped him form his own ideas.

Why does he give credit to these people? Why not take all the credit rather than spreading it around to other people? You’d think he would want to show how he thought up these ideas on his own.

If you think this way, you shouldn’t. It is always better to give credit to people who have shaped your ideas or to recognize people whose ideas support your own. Readers will find what you write more convincing when you show them that you have used other people’s ideas to help you form your own. Citing sources gives the ideas credibility.

Look at the list below. If you wanted to use any of these ideas in your writing, you would have to mention the source. How many of the following quotes can you match with the list of authors?

The point of this activity is not whether or not you could identify the authors of the quotes, but to get you thinking about using the words and ideas of other people in your own writing. Can you think of how each of these quotes could be used in an essay? Maybe it would be the starting point from which you would explain an idea of your own. Maybe it would be used as support for ideas you’re developing. Martin Luther King Jr. quotes other thinkers for these reasons in his “Letter from Birmingham Jail.” We will be looking at this essay throughout this lesson.

The quotes above could be included in an informal essay simply with such phrases as “In the words of Helen Keller . . . ” or “As Bill Cosby says . . . ” or “Sting has written that . . .” In a letter or informal essay, it is usually enough to just give the name of the author whose ideas you’re mentioning. This is what Martin Luther King Jr. does in “Letter from Birmingham Jail.” He mentions writers he is familiar with and uses their ideas to develop his own.

In a formal paper, however, you must go further than simply mentioning the authors whose ideas you’re using. You have to give a publication source for the words or ideas.

Why?

You give a publication source so a reader can do three things:

  1. Trust that you didn’t plagiarize.
  2. Check the accuracy of your reference.
  3. Assess the credibility of your reference.

In this lesson, you will learn how to decide when you will need a source citation. And you will also learn how to cite sources using parenthetical information.