of the black man that he mentions in his Critique of Black Reason (2017). Of all human beings, he says, the Negro is the only one whose flesh was turned into a commodity. Moreover, the Negro and his race have never been linked as one in European consciousness. Since the eighteenth century they have been, as an entity, the hidden and oft denied subsoil from which modern knowledge - and also of government - was rolled out.  
Obviously, the first part of this paragraph cannot apply because it does not correspond to the historical period we are dealing with here, and because of the extreme variations of origin and skin colour of those enslaved during the Middle Ages. On the other hand, the second part of his proposition, although describing a situation far removed in time and space, might not be totally devoid of meaning when it comes to thinking about otherness, similarities and dissimilarities in the Muslim world. It should not be forgotten that even back then, Arabs were not completely indifferent to the ethnic origins of the enslaved. Despite the silence and denial, some writers even had the audacity to launch a debate on the colour issue and representations of blacks. The Risāla fī Fakhr al-Sūdān, written by al-Djāhiz (died 869), the great prose writer of African descent, is clear proof of the exacerbation of social tension and ethnic prejudice. This admirable text is also a supreme historical testimony to the extent of the subjection being suffered (al-Djāhiz, op. cit., vol. I, pp. 172-226).