Normative Claims and Bridge Principles

Normative Claims and Bridge Principles

• Premises and conclusions consist of claims that can be assigned numbers.
• Claims play a role in arguments and their evaluation as premises or conclusions.
• Descriptive claims are either true or false based on physical facts observable through our senses or instruments.
• Normative claims address what should or ought to be the case, or whether something is good or bad.
• Normative claims are essential in business arguments, focusing on actions like hiring, purchasing, or investing.
• Normative claims can imply ethics, moral rights, wrongs or prudent, wise actions.
• Both descriptive and normative claims can be true or false.
• Descriptive premises cannot support a normative conclusion and vice-versa.
• Arguments attempting to bridge descriptive and normative claims need improvement, often by exposing a hidden premise.

Bridge Principles

• Bridge principles connect descriptive premises to normative conclusions.
• Bridge principles combine descriptive and normative elements.
• Bridge principles are complex normative claims specifying conditions under which something should or should not be done, or is good or bad.
• Examples of bridge principles include, "The person with the most experience should get the promotion," and "We should do whatever maximizes our profits".
• To conclude that Peter should get the promotion, it is necessary to claim that Peter has the most experience.
• Bridge principles increase the logical support that premises provide for the conclusion.

Justifying Normative Claims

• For a claim to serve as an argument's premise, it must be acceptable to the person the argument is addressed to.
• Bridge principles are normative claims that also need to be accepted.
• Arguments that have the bridge principle as a conclusion serve to ensure the premise is accepted.
• Some basic premises must be accepted when argumentation comes to an end.
• Basic normative claims may not be easily agreed upon due to the lack of ways to know them.
• Reliance on basic premises is common, as most would accept broad normative claims.
• Many bridge principles are accepted as shared moral or ethical principles, or as shared purposes.
• Providing arguments for bridge principles might be needed when resistance is encountered.
• Bridge principles are often implicit and take the role of hidden premises.

Logical Support

• An argument's premises are supposed to provide support for its conclusion if the premises are acceptable.
• A claim logically supports another claim if learning about the first claim makes it more reasonable to accept the second.
• In criminal court, the prosecutor aims to convince the jury of the defendant's guilt by presenting evidence as premises to support the conclusion.
• The defence lawyer either disputes the evidence to argue there is reasonable doubt, or claims the evidence is insufficient to warrant a conviction.
• The defence attempts to provide an alternative explanation where prosecution premises are true, but the conclusion is false.
• The less believable the alternative scenario, the less room there is for reasonable doubt, and the stronger is the premise for the conclusion.
• Logical support: Claim C is supported by a set of claims, S, if accepting S makes it more reasonable to accept C.
• The harder it is to create a plausible alternative scenario, the stronger the logical support provided by the premises.

Deductive Logic

• In weak arguments, premises do not support the conclusion and it is easy to imagine scenarios of the conclusion being false when the premises are true.
• Deductive arguments structured so that the conclusion being false when the premises are true is not possible.
• Examples of deductive logic: Argument E.
• Even if premises 1 and 2 are true, the conclusion that the bank will give the loan has to be true.
• Conditional arguments are a class of deductive argument.
• Conditional arguments use premises that specify conditions under which something is true.
• Logicians have formal methods to evaluate such arguments, but are beyond this courses cope.
• An introduction to the structure of arguments and the structure of some common, successful deductive arguments is what will be covered in this course.
• Fallacious arguments look like deductive arguments but in which the conclusion doesn't actually follow from the premises.
• Deductive and inductive arguments are different forms of argument with respective strengths and weaknesses.
• Deductive arguments have logical links between premises and conclusions, often at the expense of doubtful premises.

Conditional Arguments

• Conditional arguments use premises that specify conditions under which something is true.
• Bridge principles often take this form, specifying the descriptive condition that needs to be true for a normative conclusion to follow.
• Conditions in conditional arguments come in two forms: necessary and sufficient.
• A is a necessary condition for B means that B will not happen if A is not true.
• A is a sufficient condition for B means that if A is true, then B will also be true.
• Necessary conditions typically use "only if".
• Sufficient conditions typically use "if A, then B".
• Conditional arguments start from claiming A is a sufficient condition for B, then proceeding to affirm or deny that A or B is true, concluding the other must be true or false.
• Conditional claims make claims about the logical relationship between two other claims.
• Sometimes, conditional arguments support conclusions by stating conditions where a claim is true, then denying that the further claim is true leading to a negative conclusion.