Blake was certainly one of the most outspoken critic of the political establishment in his day; I don't think either he or Clare were really crazy -maybe Clare was because he had been driven mad by the times

Satirist Jonathan Swift left money in his will to found the first mental asylum in Ireland . He wrote about how ,before the seventeenth and eighteenth century land seizures in Ireland, it would have been possible to count the number of genuinely mad people in the country on perhaps two hands . Within twenty years of the confiscations you couldn’t walk a road or laneway without encountering desperate lunatics .