Pacisco\Toulmin_Model\Grounds

Grounds are the evidence or data that are used to substantiate an argument.

In Pacisco they take the form of claims that will have their own supporting or rebutting cases.  They may make reference to external sources (book, journal paper, newspaper or website).

When creating an argument the grounds element will accept simple and compound propositions, where a simple proposition is a claim and a compound proposition is a claim modified by:

• negation; the ‘not’ operator

or connected with other claims by:

• conjunction; the ‘and’ operator
• disjunction; the ‘or’ operator
• exclusive disjunction; the ‘either_or’ operator

The precedence or binding of operators can be confirmed or modified by the use of parentheses.

The following are examples of grounds:

The boiling point of water at standard atmospheric pressure is 100°C.

not Glass is a supercooled liquid.

The Prime Minister is a fool. or The Prime Minister is a liar.

When individual claims are entered for the first time as propositions in the grounds element of an argument, the author is making a commitment to substantiate them subsequently with a supporting or rebutting argument.

Pre-existing similarly worded claims will be presented as the claim is being composed so that, if appropriate they can be selected in place of the new claim, thereby linking the argument in to an existing network of reasoning.