What is science and what are five reasons that it is important?

Like many terms whose meaning at first seems obvious, the
term "science" is actually quite difficult to define precisely. Or perhaps it is more
accurate to say that the term has been defined in many different ways (and understood in
many different senses) over the course of many centuries, so that defining it in any
limited, strict, or single sense is very difficult.  One has only to look at the many
ways the term has been used to realize how difficult defining it precisely really is
(see The Oxford English
Dictionary).

For present purposes, the
definitions provided at dictionary.com seem
sufficient:

1.
a branch of
knowledge or study dealing with a body of facts or truths systematically arranged and
showing the operation of general laws: the mathematical sciences.


2.
systematic knowledge of the physical or material
world gained through observation and experimentation.

3.

any of the branches of natural or physical science.

4.

systematized knowledge in general.

5.

knowledge, as of facts or principles; knowledge gained by systematic study.


6.
a particular branch of knowledge.

7.

skill, especially reflecting a precise application of facts or principles;
proficiency.

Of these definitions,
perhaps # 5 most closely corresponds to what most people have in mind when they speak of
"science."

The importance of "knowledge gained by systematic study"
is hard to over-estimate. Here are five reasons why such knowledge is
important:

• It is
  knowledge. In other words, it is a set of claims and
  assertions in which we can have enormous confidence because those claims have been
  tested and have proven reliable.  This is not to say that science is never wrong or
  infallible; indeed, it is precisely the fact that scientific claims can be falsified --
  that is, proven untrue -- that we can have great confidence that generally accepted
  claims of science are reliable.


• It makes possible the
  manipulation of matter, allowing us to build things like
  bridges and airplanes and have good reasons to assume that they will not collapse or
  crash.  Without science, material progress by humans would be haphazard and
  slow.


• It contains the possibility of
  growing knowledge. One scientific "discovery" often leads
  to another, and that one to another, and that one to another, in ways that are not true
  in other fields of human endeavor.


• It can be
  systematically taught. It does not rely as much as other
  kinds of thinking on inspiration, guess work, intuition, or chance.  All these factors
  play some role in scientific discovery, but once a discovery has
  been made it can be taught to people as a truth in a way that is not true in other, less
  rigorous fields.


• It is convincing not
  because it is rhetorically attractive or emotionally satisfying but because it has
  enormous predictive value: science allows us to peer into
  the future in ways that other fields of study do not and
  cannot.