Ruth Arthur's books have a soothing air of unreality about them; they deal with familiar, entirely human emotions and behaviour, but always from a safe distance…. [In] The Little Dark Thorn the heroine's problems have already been resolved before the reader hears of them, for Merrie tells her own story, from the tranquil vantage point of someone who has begun to rationalise her feelings and to see her past behaviour in perspective…. There are homely details of everyday life that recreate different backgrounds of very distinctive identities, the story Merrie tells is an interesting one. Like all Ruth Arthur's books its appeal is specifically feminine. It is a well-written, quiet, 'comfortable' book over which the soft-hearted may shed a tear or two without being greatly moved. (p. 193)