RI Answers to Recap Quiz for Scepticism Unit 1

1 Answers to Recap Quiz for Scepticism Unit 1 1) PS can doubt even those things that we normally don’t doubt (like our senses, the existence of the external world) whereas OS doesn’t. Why? Because PS demands zero uncertainty for knowledge whereas OS allows for a little uncertainty 2) In asking for the justification behind our knowledge claims, we are trying to determine what we know and to what degree of certainty we know them. Upshot: if we can refute the sceptic’s attack, we will have vindicated our knowledge claims. (Of course, the converse is true.) 3) TB p17 – the idea that we could all just be in our own closed belief systems such that no matter what contradictory belief comes in, we refuse to accept 4) Infinite Regress, Illusions, Dreaming, Evil Demon, Constant Conjunction 5) Infinite Regress: keep asking for justification such that because there seems to be no stop to this process, there is never proper justification and hence no knowledge Illusions: my senses have deceived me sometimes and thus we cannot trust our senses [objection: but only in poor conditions, not good conditions] Dreaming: but we CAN dream in good conditions and thus still doubt our senses in good conditions [objection: but there are simpler things that make up dreams – these must come from somewhere and thus still exist] Evil Demon: but we could just be all existing in some mental realm and everything is a figment of our imagination created by the Evil Demon Constant Conjunction: we can't see causation. We only see event A happening and then B happening. At best, it has been constantly conjoined. But there is no guarantee that they will stay constantly conjoined in the future; it might not. cf. Russell's Turkey argument further, as the TB points out (p19), depending on how the past has worked to predict the future is a circular argument. Problem of Induction – that it is circular. For the reason why we think that Science is certain is because these generalisations from thousands of observations do seem intuitively justified. This is because we think that the

2 future always resembles the past, i.e. the Uniformity Principle. Applying this to the previous metal e.g.: P1: All the metals that we have observed so far expand when heated P2: The future will resemble the past (UP) C1: All metals will expand when heated (P1-2) Disregarding for now how the argument appears now to be a valid (hence deductive) one, the issue here is the truth of P2, the UP. P2 only appears to be true because it is based on past observations of how, in the past, the future had indeed resembled the past. In other words, the UP is the result of a generalisation, i.e. an inductive inference. This looks like: P3: In the past, the future resembled the past P4: The future will resemble the past C2/P2: The future will resemble the past (P3-4) What this clearly shows however is that the argument is circular since the conclusion is itself one of the pre