skepticism

Short definition from Wiktionary

Noun

1. 1
   The practice or philosophy of being a skeptic.
2. 2
   A studied attitude of questioning and doubt.
3. 3
   The doctrine that absolute knowledge is not possible.
4. 4
   A methodology that starts from a neutral standpoint and aims to acquire certainty through scientific or logical observation.
5. 5
   Doubt or disbelief of religious doctrines.