In The Origin of Species, Charles Darwin wrote timidly:
Light will be thrown on the origin of man and his history.
As Richard Dawkins points out in A Devil's Chaplain, Darwin's monumental understatement is on a par with the famous words of James Watson and Francis Crick in 1953, on the potential of their discovery of the structure of DNA:
This structure has novel features which are of considerable biological interest. […] It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.
Great scientists rarely shout. They rarely need to.