#skeptic__sceptic__doubter  someone who habitually doubts accepted beliefs
  supertype:  intellectual__intellect  a person who uses the mind creatively
  subtype:  doubting_Thomas  someone who demands physical evidence in order to be convinced (especially when this demand is out of place)
  subtype:  pessimist  a person who expects the worst
     subtype:  defeatist__negativist  someone who is resigned to defeat

No statement uses or specializes skeptic; click here to add one.