 In the absence of any text by Gregory on the topic, we cannot be sure that he reasoned like this from Heytesbury’s position. But for whatever reason, he apparently did confine insolubles to spoken and written language; for Gregory there are no insolubles in mental language. An insoluble proposition in spoken or written language corresponds to and expresses not the mental proposition one would normally expect on the basis of the usual linguistic conventions, but a complex and non-paradoxical mental proposition.