‘Between Creator and creature there can be remarked no similarity so great that a greater dissimilarity between them cannot be seen’. With these words the Fourth Lateran Council of 1215 concluded its condemnation of the doctrine of the Trinity held by Joachim of Fiore (d. 1202). The council based its assessment on Joachim's use of biblical texts as analogies for divine unity. For Joachim had, in the opinion of those who judged him, reduced the irreducible gap between God and His creatures by making God like His creatures. He had allegedly emphasised the principle of similarity at the expense of that of dissimilarity. The result was the dilution of the type of unity appropriate to the Trinity from a unity of essence to a mere unity of collection, no more binding than the spiritual unity among the faithful as expounded in many passages in the Bible, most importantly in John xvii. 22: ‘And the glory which thou has given me, I have given to them: that they may be one, as we also are one.’