{ 1 } - that any genuine truth claim is either empirical or analytic.
{ 2 } - that logic can prove that things have positive value.
{ 3 } - an optimistic and logical attitude toward life.
{ 4 } - that only matter exists.

Logical positivism is a view about which statements make genuine truth claims (claims that are true or false). It says that a genuine truth claim has to be either empirical (testable by sense experience) or analytic (true by definition).

This view was popular once, but it isn't popular today. There are good reason for this loss of popularity. For one thing, the view itself isn't empirical or analytic -- and so on its own terms can't be true. So the view is self-refuting.