The question (10 marks)
State the three laws of thought as applied to propositions, answer the standard objection to each, and discuss the view that they are the necessary and sufficient conditions of valid thinking. (10 marks)
MU Module I, head 1.6; pack ch. 02.
Plan your answer on paper before you look at the authorities — issue first, then the rule, then apply it to these facts.
It tests Unit 1 · Introduction to Logical and Legal Reasoning of Logic – I.
Authorities you will need
- Keynes, Formal Logic, on the negative function of the laws
- Mill, System of Logic, objecting that the unmeaning is a third possibility
- Bertrand Russell, on the dependence of double negation on Excluded Middle
- Aristotle, from whom the three laws descend
How an answer is marked
A full-marks answer names the issue in one line, states the rule with its section, cites the authority, applies it to these facts and concludes — in that order. The app's model answer for this question is written in exactly that shape, with a checklist to mark your own attempt against.