“Diax’s Rake: A pithy phrase, uttered by Diax on the steps of the Temple of Orithena when he was driving out the fortune-tellers with a gardener’s rake. Its general important is that one should never believe a thing only because one wishes that it were true….” (Neal Stephenson, 2008, Anathem, p. 895. London: Atlantic Books)In his latest novel, science fiction writer Neal Stephenson posits an alternate world in which there are multiple monastic orders of scientist-philosopher monks. One them, Saunt (short for “savant”) Diax is famous for having driven the fortune tellers out of the Temple of Orithena (equivalent to the Greek goddess Athena), whilst saying “Never believe a thing simply because you want it to be true.”
This invention is characteristic of what Stephenson does throughout the book, alluding to multiple cultural references familiar to us, and blending them together to yield something strange but familiar. Here, he appears to have combined Occam’s Razor (another sharp domestic implement, applied to facilitate logical thinking), Jesus driving the money changers from the Temple in Jerusalem, and a saying of the Greek historian Thucydides (“It is a habit of mankind to entrust to careless hope what they long for, and to use sovereign reason to thrust aside what they do not desire.” See: anathem.wikia.com/wiki/Diax’s_Rake).
It seems to me that Hermeneutic Single Case Effiacy Design (HSCED) is a version of Diax’s Rake applied to the purpose of inferring causality in single therapy cases. Against the therapist and researcher’s desire to show that a client has changed because of therapy, HSCED brings forth a logical rake consisting of eight tines: four nonchange explanations and four nontherapy alternative explanations that are applied to the case data in order to combat the wish to see one’s therapy as effective.
Stephenson’s apparent allusion to Thucydides is particularly appropriate to HSCED. According to the Wikipedia article, the Greek historian is known as “the father of ‘scientific history’ due to his strict standards of evidence-gathering and analysis in terms of cause and effect without reference to intervention by the gods…”. HSCED is essentially a careful application of methods used by historians to psychotherapy case study research, a systematic method for undoing the natural desire for one’s favoured therapy to be effective.
Since the original development of the method, we have tried to develop it further by separating out two opposing sides, known as affirmative and sceptic. The Affirmative side’s task is look for replicated evidence connecting therapy to client change, while the Sceptic side’s job is to apply Diax’s Rake by looking for other explanations for apparent client change. In other words, HSCED assumes that Diax’s Rake is not enough, but must be balanced by a careful search for supporting evidence, which can then be brought against Diaxian skepticism in a search for the truth whether and how the client has changed. Thus, a fitting response to Diax's Rake might be, "But gardens do not grow by rakes alone!".
In fact, Stephenson’s scientist-philosopher monks would probably agree that the real value of Diax’s Rake is precisely in invoking skepticism as a means to inspire stronger arguments that mere wishful thinking.