happen in the world from their views on what they would like to happen
example, until the eighteenth century almost everyone believed that Earth
was only a few thousand years old. Evidence then began to accumulate
that Earth was billions of years old. This evidence was hard for most
people to accept, since it ran counter to a literal reading of many religious
texts. Many did not want to believe the evidence. Nevertheless, scientists,
many of whom were religious, continued their research because they
refused to allow their feelings about what they wanted to believe to affect
their scientific search for the truth. Eventually, all scientists and most
members of the public came to accept that Earth is about 4.5 billion years
old.
Distinguishing what is actually true from what we would like to be true requires distinguishing
between positive and normative statements.Examples of both types of statements are given in Table 2-1. All five
positive statements in the table are assertions about the nature of the
world in which we live. In contrast, the five normative statements involve
value judgments. Notice two things about the positive/normative
distinction. First, positive statements need not be true. Statement C is
almost certainly false, and yet it is positive, not normative. Second, the
inclusion of a value judgment in a statement does not necessarily make
the statement itself normative. Statement D is a positive statement about
the value judgments that people hold. We could conduct a survey to
check if people really do prefer low unemployment to low inflation. We
could ask them and we could observe how they voted. There is no need