RI Critical Thinking 2023 Exercise F Answers

Exercise F Evaluate the following arguments. Draw an arrow diagram first. 1. *A ship has gone down in the ocean and half the passengers have been killed. Your best friend Angela was on board but you do not know if she was one of the survivors. At once, you utter a prayer to God that she survived. “Your prayer is pointless. For your prayer is superfluous if Angela survived. And if she did not survive, then God can hardly answer your prayer since, despite all His powers, he cannot do the impossible, and it is impossible to alter the past.” Deductive argument. There seems to be a few weak points in the argument. One, that God works IN time. Surely God, being almighty, could be out of time such that your prayer, retrospective as it may seem to you, is NOT retrospective to Him. If so, then whether Angela survives or not could be due to your prayer. Two, is it really impossible to alter the past? Three, can God being all-powerful be unable to do the impossible? Dilemma is a valid form of argument that goes something like this: Either p or q If p then r If q then r Therefore r 2. Whatever consists mostly of empty space isn’t solid. But the chair I sit on consists mostly of empty space since it consists of billions of atoms, each of which consists mostly of empty space. This last is true since each atom consists of a tiny central core If Angela survived, your prayer is superfluous God, despite all His powers, cannot do the impossible It is impossible to alter the past God cannot alter the past If Angela did not survive, then your prayer is asking God to alter the past Your prayer to God is that Angela survived If Angela did not survive, then God cannot answer your prayer If God cannot answer your prayer, then your prayer is pointless If Angela did not survive, then your prayer is pointless Your prayer to God is that Angela survived If your prayer is superfluous, then your prayer is pointless If Angela survived, then your prayer is pointless Either Angela survived or Angela did not survive Your prayer is pointless Not clear if valid Not clear if valid Valid Valid Hypothetical syllogism Hypothetical syllogism Dilemma An atom consists of a tiny central core surrounded by tiny electrons situated at a relatively large distance from the core

surrounded by tiny electrons situated at a relatively large distance from the core. It follows that the chair I sit on isn’t solid. How on earth does it support my weight? The premise, “Whatever consists mostly of empty space isn’t solid”, is false. To prove this, raise a counter-example. A simple one would be a hollow box. It consists mostly of empty space but is solid. Counter-examples are a great way to prove that an argument is unsound by showing that a particular premise is false. 3. Either that bomb is going to kill me or it is not. If it is going to kill me, then any precautions I take will be ineffective. But if it is not going to kill me, then a