Noun
One who doubts; one whose opinion is unsettled; one who scruples.
Source: Webster's dictionaryTest yourself on mankind. It is something that makes the doubter doubt, the believer believe. Franz Kafka
The believer who has never doubted will hardly convert a doubter. Marie von Ebner-Eschenbach
They reckon ill who leave me out; When me they fly, I am the wings; I am the doubter and the doubt; And I the hymn the Brahmin sings. Ralph Waldo Emerson
An agnostic is a doubter. The word is generally applied to those who doubt the verity of accepted religious creeds of faiths. Everyone is an agnostic as to the beliefs or creeds they do not accept. Clarence Darrow
He who trusts is happy; the doubter is wise. Hungarian Proverb
The believer is happy; the doubter is wise. Hungarian Proverb