Ph103: Discussion Questions 9

Short Answer Questions

1. What roles do a 1km gold sphere and a 1km uranium sphere play in helping us describe laws?
2. Summarize John Roberts' argument that there are no laws in the social sciences.
3. What is a hedged law?

For Further Discussion

• The special character of laws. Laws are a special kind of fact. Consider the following.
  • No ordinary bird can fly faster than a peregrine falcon in air.
  • No ordinary matter can move faster than the speed of light in a vacuum.
  • The evenness or oddness of a number is determined by whether or not it is evenly divisible by 2.
  • The evolution of species is determined by natural and sexual selection.
  (a) Which of these statements can be considered a law, and why? (b) Can you think of any other facts in science that are plausibly laws? (c) Can you think of any facts in social science that are plausibly laws?
• The law of supply and demand. There are many aspects to the law of supply and demand. But let's just consider a simplified version, which says that if the supply is fixed and the demand goes up in a competitive market, then the price also goes up.
  • Why does Roberts call this a hedged law?
  • How many circumstances can you think of in which this law fails to hold?
  • Suppose we adjust the law of supply and demand to be the statement that the italicised statement above is true, except in circumstances in which it isn't. Can we consider this a law? Why or why not?
  • Can you think of a better way to revise the law of supply and demand so that it is a law?
  • What does Roberts conclude about hedged laws, and why?
  • Do you agree with Roberts' conclusion?
• The nature of the social sciences. (a) Roberts suggests that every social scientific description must leave open the possibility that a comet obliterates the planet. If this is right, then is it ever possible to have a non-hedged law in the social sciences?
  
  (b) Does this argument work for physics as well? That is, given that physics must leave open the possibility of an apocalyptic comet, is it ever possible to have a non-hedged law of physics?