‘If P, then Q’ One of the most common and important uses of the form: (Explanation B) Causes and Effects One of the most common and important uses of the form: ‘If P, then Q’ is to suggest that event P is a cause of event Q

Event Q is then said to be an effect of event P. (Explanation B) Causes and Effects Consider the sentence, :‘If you have a cold, then you have a runny nose’, It suggests that having a cold (P) is a cause of having a runny nose (Q). Event Q is then said to be an effect of event P.

Notice that an effect can, in turn, be a cause of something else. (Explanation B) Causes and Effects Notice that an effect can, in turn, be a cause of something else. For example, if you have a runny nose (Q), (then) you want to sniff (R)

(Explanation B) Causes and Effects In pairs or as a whole group, discuss whether getting a cold might itself be an effect of a previous cause (as well as being a cause of a runny nose in the near future). Express any cause you can think of in the form: ‘If …, then you might get a cold’. You could also discuss whether having a runny nose might have other effects (apart from wanting to sniff).

(Exercise B, 1–4) Causal Chains See if you can make a chain of causes and effects, using the example of catching a cold: 1. ‘If …, then you might catch a cold, and if you catch a cold, then you might …, and if you …, then you might …, etc.’ 2. Discuss if there only one such chain possible, or whether there could there be many different ones. 3. Make up a different causal chain, using events that have actually happened, with perhaps 5 events in the chain.

(Exercise B, 1–4) Causal Chains 4. As a whole group, (prepare for some mind-boggling questions!) discuss: Could an actual causal chain have been different from how it was? (b) If so, would it have been by cause or by chance?

(Exercise B, 5 - 8) Immediate Causes/Effects In pairs or groups 5. Discuss how many causes might lead up to a particular event, such as your catching your last cold or (more challenging!) your discussing this question. 6. Discuss whether in some cases we can say that event P was the last event before event Q, and ‘triggered’ or caused Q to happen. If so, be ready to give an example to the whole group.

(Exercise B, 5 - 8) Immediate Causes/Effects 7. As a whole group, share your thoughts and examples, and discuss whether there is actually a ‘trigger’ or ‘immediate cause’ in every case. 8. If so, agree on one example where it is clear what the immediate cause is, along with its immediate effect, and then in pairs or groups again make up 2 more good examples.