# 4 Questions to Consider

1. Suppose Marcelo says that he knows the moon is made of green cheese. You ask for his justification, and he says that he works in a cheese shop and so he knows cheese when he sees it. Thus, he knows that the moon is made of green cheese. You want to show Marcelo that he’s wrong, but in looking things up, you find a credible article in Nature claiming that, in fact, there is evidence of trace elements of green cheese in lunar soil. Now what do you say to Marcelo?
1. Petra adds 59,086 and 63,212 and gets 122,398. She is obsessive about such things, so she checks six times and gets the same answer each time. Why is she wrong to say she knows that 59,086 plus 63,212 equals 122,398? Once you have answered this question, consider this one: how many times did you check the calculation? How do you know that Petra is wrong?
1. Imagine encountering a society that has built rocket ships, atomic clocks, and X-ray machines. But when you talk with their scientists, they believe they are harnessing the spirits of demons locked inside in the earth, and their science textbooks look completely different from our science textbooks. Put the following responses in order from “least plausible” to “most plausible”:
1. These people believe false things, and they have unknowingly built some very impressive devices.
2. These people believe things which seem false, but if we studied their beliefs more carefully, we would find that they have the same science we have, but expressed in wildly different terms.
3. What these people believe is just as true as what we believe, and their science is radically different from ours; the two sciences are not merely the same knowledge expressed in different terms (so #2 is false).