Philosophical skepticism (Greek "σκέψις" - "skepsis" meaning "enquiry") is a school of philosophical thought of skepticism that began in Ancient Greece and a method that crosses many different cultures. Many skeptics examine the meaning systems of their times, and this can often result in a position of doubt. This skepticism can be either disbelief in philosophical solutions, agnosticism, or even rejecting the reality of the outside world. One kind of scientific skepticism talks about looking into claims that lack evidence that can be seen.