The word is solipsism. Pronounced /ˈsälipˌsizəm/. This word is a noun and is defined as
The view or theory that the self is all that can be known to exist.
Used in a sentence: With the advancement of technology, science and innovation that has been further influenced by the SOLIPSISTIC viewpoint of man’s place in the universe, it has caused many to further distance themselves from God, Christ and the gift of salvation.