Arguments are usually expressed in a stream of words. Sometimes we say them out loud, and sometimes we write them down in written form (letters, essays, reports etc.). The idea is to convey arguments from one person (the ‘author’) to others (the ‘audience’) using words as the vehicle or medium of communication.

The challenge facing the audience is to take the stream of words in, and figure out what the argument is. That is, the audience has to identify the claims and how they ‘hang together’ in an argumentative structure. This is quite a difficult thing to do, especially as arguments get more complex.

Fortunately, authors can make life a little easier for their audiences by inserting little ‘helpers’ – words or phrases which explicitly signal the structure of the reasoning. These logical signposts are known as argument structure indicators, or just indicators:

    An [argument structure] indicator is a word or phrase whose role in

    an argumentative text is to help the audience identify the structure

    of the reasoning.

Examples

Here is a typical piece of argumentative writing:

    Grad students can start successful companies. The three big powers on the Internet now are Yahoo, Google, and Microsoft. Average age of their founders: 24. And if grad students can do it, why not undergrads?

Note that, as is often the case, the author has provided no argument structure indicators. Here is a version rewritten to include some indicators:

    The three big powers on the Internet now are Yahoo, Google, and Microsoft. Average age of their founders: 24. Together, these facts establish that grad students can start successful companies. Hence, undergrads should be able to start successful companies.

The rewritten version is more labored, but it does make the structure of the reasoning more obvious.

Types of Argument Structure Indicators

There are dozens of words or phrases that are commonly used as indicators. It is common to classify indicators in terms of the nature of what they are pointing to, i.e., what immediately follows them. Here is a small selection of classic argument structure indicators:

Indicators are Clues

Indicators are best thought of as clues to argument structure. Some (e.g., proves that…) are highly reliable. Others are very ambiguous; they may be indicating argument structure, but they may also be playing a quite different role. The classic reason indicator because is a good example; very often, it is pointing not to a reason, but to an explanation.

Lack of Co-premise Indicators

It is a remarkable fact that, while there are dozens of reason indicators and contention indicators, there are almost no words or phrases which commonly indicate that two claims are co-premises.

The word and is often used, but and has many other uses as well. Identifying co-premise relationships in typical argumentative prose requires a very strong intuitive sense for how arguments hang together.

See also: Topics Identifying Arguments in Prose, Holding Hands Principle and InferenceObjection