Incidentally, on the Summer thread, AdC countered my assertion that The Dillards' (post-Doug) version of "Reason To Believe" is the best interpretation of the song by reference to Tim Hardin's original.
Fair comment, and it's a matter of preference. Hardin's version is stripped down with the man giving it the usual rough vocals (Hardin was not a great vocalist, it's fair to say). The Dillards did the harmonising thing, and their interpretation certainly is more beautiful than Hardin's. The Dillards also deliver the key line, "Knowing that you lied straight-faced while I cried" more effectively, bit that is, of course, also totally subjective.
Bobby Darin did a pretty good version of it, too. He and Hardin were pals: Hardin wrote "If I Were A Carpenter" for Darin, and Darin gave Hardin "Simple Song Of Freedom".