Can the Constitution of a Fruit Fly be Written?

This essay, written for From morality to law and back again: Liber amicorum for John Gardner (Michelle Dempsey and Francois Tanguay-Renaud, eds., Oxford University Press), is in conversation with the late John Gardner's essay "Can there be a written constitution?". It interrogates Gardner's strategy of answering his title question by reference to HLA Hart's secondary rules and suggests that, by doing so, certain aspects of a constitution are closed off from consideration or obscured from view. Among those is whether a constitution constitutes a legal system or, more broadly, a state or government; whether Hart's secondary rules can account for the executive function of government; and whether rights requiring legislative action can be explained in the frame of secondary rules. The essay concludes by suggesting that, without holding in view a more complete picture of a constitution, Gardner's title question may ask the wrong question in a manner analogous to one who asks if the constitution of a fruit fly can be written.