I have been reading, with great interest, a recently-published article in The Journal of Imperial and Commonwealth History by a graduate student (Aaron Willis) at the University of Notre Dame: “The standing of new subjects: Grenada and the Protestant constitution after the Treaty of Paris (1763)“.
Willis’s paper concerns the political difficulties which surrounded the incorporation of French Catholics into the British Empire following the ceding of Grenada at the end of the Seven Years’ War. In broad terms, opinion was divided among islanders as to the extent to which political rights which applied to British Protestants should be extended to French Catholics. These divisions resulted in political stalemate which lasted through much of the late 1760s and early 1770s. Willis offers a neat summary of the principal pamphlets which were issued during this period and argued, at turns, for and against the rights of French Catholics.
There is some evidence to suggest that one of these pamphlets—Audi alteram partem (1770)—which Willis describes as being “[t]he most sustained defence of Catholic rights” was co-authored by Macintosh. That, at least, was the opinion of an anonymous reviewer writing in The Political Register (May, 1770) who noted “It is almost needless to add, that Mr. Mackintosh [sic], Col. [James] Johnstone, and Mr. Scott are the Authors of Audi Alteram Partem…and are the agents and abettors of the Romish party there”. Clearly it will require some digging to determine whether or not there is any validity in this claim, or that Macintosh was “known to be zealous in the cause of the Roman Catholic French subjects at Grenada”. I would think, however, the latter is a safe bet.