Constructing and Reconstructing Arguments

Learn what an argument is in the logical sense, how to tell arguments apart from explanations and interpretations, and how to reconstruct a messy real-world argument into clear premises and a conclusion.

1 Introduction

Whenever you defend a position in a seminar paper, evaluate a business plan, or assess a claim in the news, you are working with arguments. Being able to take a tangled piece of prose and lay bare its underlying structure — what is being claimed, and on what grounds — is one of the most useful and transferable skills in academic and professional life.

This page introduces the logical notion of an argument, separates it from things that look similar but are not arguments, and gives you a step-by-step procedure for reconstructing an argument into a clear, evaluable form. Once an argument is reconstructed, you can assess whether it actually works — that is the subject of Evaluating Arguments: Validity, Soundness and Fallacies.

2 What is an Argument?

In everyday language, an “argument” is a quarrel. In logic it means something more specific and more useful:

An argument is a set of statements consisting of premises and a conclusion. The premises are statements intended to give supporting evidence; the conclusion is what is allegedly supported by them.

So an argument has two kinds of parts:

1. Premise(s) — one or more declarative statements offered in support of the conclusion. A premise is the kind of sentence we can assign a truth value to (true or false). Importantly, a premise does not have to be true for the argument to do its work — we can reason from premises whose truth we are still examining.
2. Conclusion — the statement the premises are meant to establish.

2.1 Statements have truth values

Only declarative statements can serve as premises or conclusions, because only they can be true or false. Compare:

• “You ordered mint-flavoured ice cream?!” — a question, no truth value.
• “This statement is false.” — a paradox, no stable truth value.
• “The atomic number of hydrogen is 1 and the atomic number of helium is 2.” — a declarative statement with a definite truth value.

A simple worked example of an argument:

Premise 1: If it rains, the street is wet. Premise 2: It rains. Conclusion: The street is wet.

3 What an Argument is Not

A common source of confusion is mistaking other kinds of utterance for arguments. Three contrasts are worth keeping straight.

3.1 Argument vs. explanation

• An argument answers: what are the reasons to believe a conclusion?
• An explanation answers: why is something the case? — it takes the fact as already accepted and tells you what produced it.

“The lights went out because there was a power outage.” — explanation (we already accept the lights went out; we are told the cause).

“The suspect must be guilty because their fingerprints were at the scene.” — argument (we are being given a reason to believe a contested claim).

Notice that the word “because” appears in both — so you cannot rely on signal words alone. Ask instead whether the conclusion is something in dispute that needs support (argument), or something accepted that is being accounted for (explanation).

3.2 Argument vs. interpretation and definition

• An interpretation asks: what could this sentence mean?
• A definition asks: what is X? Definitions come in two useful flavours:
  • a lexical definition explains current usage of a term;
  • a stipulative definition fixes a specific usage for a particular context (very common in research, where you define how you will use a contested term).

These are not arguments — but a good argument often depends on them, because vague or shifting terms are a frequent source of bad reasoning.

4 Reconstructing an Argument

Real arguments are rarely stated in tidy premise–conclusion form. Reconstruction is the skill of turning prose into a clear standard form so it can be evaluated. As the philosopher Chris Bobonich puts it, “Once you learn to dissect and reconstruct an argument, evaluating and analyzing the argument will become much easier.”

A reconstruction does several things at once:

• makes implicit premises explicit (arguments almost always leave assumptions unstated);
• states each premise clearly and separately;
• sorts the premises into the right order;
• and asks, beyond mere correctness, whether the argument is actually good.

4.1 A step-by-step procedure

1. Find the conclusion of the overall argument. What is the author ultimately trying to get you to accept?
2. Find the core — the central premise(s) that most directly support the conclusion.
3. Find the supporting premises that back up the core.
4. If needed, identify sub-premises that support the central and supporting premises.
5. Put it together and write it down in logical form, labelling premises (P1, P2, …) and the conclusion (C).

4.2 Worked example

Take the everyday claim:

“Philosophy is valueless because it cannot help us make money.”

A weak reconstruction piles in irrelevant material:

P1: Philosophy cannot help us make money. P2: Computer science can help us make money. P3: Philosophy is different from computer science. P4: If X can help us make money, then X is valuable. C: Therefore, philosophy is valueless. ❌

A clean reconstruction keeps only what the conclusion actually needs, and makes the hidden general premise explicit:

P1: If a thing cannot help us make money, then it is valueless. P2: Philosophy cannot help us make money. C: (from P1 and P2) Therefore, philosophy is valueless. ✓

The second version is better not because the conclusion is true — you may well reject P1 — but because the structure is now transparent and can be evaluated. (Indeed, making P1 explicit is exactly what lets us see the argument’s weakest point.)

4.3 Criteria for a good reconstruction

For an original argument T and your reconstruction R:

1. R respects T — it is a faithful rendering of what was actually argued.
2. R is a valid argument in standard form — the conclusion genuinely follows from the premises.
3. No redundant premises — every premise in R is necessary to make R valid.
4. R is a charitable reading of T — where the original is ambiguous, you reconstruct the strongest reasonable version rather than a strawman.

Note🎓 MA / PhD

Reconstructing complex, multi-step arguments — where intermediate conclusions become premises for later steps — is a core scholarly skill. A useful exercise is to take a paragraph of argumentative prose from a paper in your field and render it as a chain of linked arguments (C1 feeds into P-of-the-next-step, and so on). The principle of charity is not merely politeness: a reconstruction that defeats only a weak version of an opponent’s view tells you nothing about whether the real view is defensible.

5 Summary

• An argument is a set of statements: premises offered in support of a conclusion. Only declarative statements (which have truth values) can play these roles.
• Arguments differ from explanations (why something is the case), interpretations (what a sentence means), and definitions (what a term is).
• Reconstruction turns messy prose into standard form by making implicit premises explicit and ordering them clearly.
• A good reconstruction is faithful, valid, free of redundant premises, and charitable.

6 What to Read Next

• Propositional Logic: Operators, Truth Tables and Syllogisms — the formal tools for combining and analysing statements.
• Evaluating Arguments: Validity, Soundness and Fallacies — how to judge whether a reconstructed argument actually works.

7 Further Reading

• Gensler, H. J. (2010). Introduction to Logic (2nd ed.). Routledge.
• Kahane, H., Hausman, A., & Boardman, F. (2021). Logic and Philosophy: A Modern Introduction (13th ed.). Hackett.