In his most entertaining and scholarly letter, Diskin correctly characterizes the study of Roos et al1 as a randomized, prospective double-blind trial, and he is more than willing to accept its conclusions (in spite of the shortcomings pointed out in my editorial2), while he decries the growing use of practice guidelines. The inconsistency relates to the fact that practice guidelines are generally derived from critical analyses by acknowledged experts of not one but many randomized, prospective, double-blind trials. Thus, the basis for my recommendations is to subscribe to the larger scientific portfolio, whereas to do otherwise would clearly risk being the one “leaving early” from the scientific revolution. As an apparent student of medical history in general, and the writings of William Osler in particular, Diskin might do well to recall the admonition of Osler (that originated with Alexander Pope) to “be not the first by whom the new are tried, nor yet the last to lay the old aside.” Yes, the “standard of care” definition does relate to prudent physicians of comparable training in the same community, but prudence dictates that they primum non nocere. The reader is referred back to my editorial2 for the arguments that I believe support the traditional approach to initiation of levothyroxine therapy. However, I will reemphasize that both the early high-dose group and the control group in the study by Roos et al1 reported improvement in symptoms at the same rate—so what was gained other than risk of an adverse outcome? And if Diskin is implying that I had advocated a “monolithic” standard of care, I invite him to reread my Editorial and not rush to judgment. Finally, I will take the liberty of inferring that Diskin's characterization of “wisdom from the Ancients” constituted an ad hominem attribution and if so, I am grateful at least for the “wisdom” component.