Most philosophers in the Middle Ages agreed that the compositionality thesis is wrong: points do not compose a line. And in general they denied that continua are composed of indivisible atoms. Yet despite all this, there were very bright people in the Middle Ages who believed and defended the compositionality thesis: they said that in fact continua were composed of indivisible atoms. Today we call these people indivisibilists and their view is called indivisibilism. Two of the most famous indivisibilists in England were Henry Harclay, who was head of Oxford University in 1312, and Walter Chatton.