The Life Force of your Thesis

Types of argument: the categorical syllogism

Arguments are the life force of your thesis. Claims are easy to make, but unless that claim comes as part of an argument then it is of limited value. Rather, it is the presence and strength of the arguments that will determine whether your thesis will be successful. What, then, is an argument?

An argument may be defined as a claim supported by reasons for accepting the claim. It is the reasons that do the work of the argument. Without them, a claim remains a bare assertion, but as soon as a reason is provided to back up the claim then an argument is formed. Although arguments may be complex and involve more than one reason, and perhaps also multiple, connected claims, they can be reduced to relatively simple forms. Perhaps the most paradigmatic and classical form is the categorical syllogism.

A categorical syllogism is a deductive argument that relies on two premises to justify a conclusion. In this particular form, the conclusion equates to the claim and the two premises provide the reasons to accept the claim, or conclusion. These premises are normally characterised as a major premise and a minor premise. The major premise is the one that contains the predicate of the conclusion, while the minor premise contains the subject of the conclusion.

Consider a simple example:

  • All whales are mammals.
  • Felix is a whale.
  • Therefore, Felix is a mammal.

Here the predicate term is mammal, which makes the first sentence the major premise. Felix is the subject term, which makes the second statement the minor premise. The third sentence is the conclusion, or claim. To present this less formally, one might argue: Because Felix is a whale (reason) and all whales are mammals (reason), then Felix is a mammal (claim).

This is only a very basic introduction, but we will build on it in future articles. If you need support or advice to help you develop the arguments in your thesis, the PhD Consultancy can provide experts from a wide range of academic disciplines.