text: [19] But take the number of slaves according to Gibbon's computation at only half the entire population what a prodigious abstraction must this multitude of slaves have made from the physical and moral strength of the empire! Half the people requiring food needing restraint incapable of trust and yet adding nothing to the muster-roll of the legions or the persons by whom the fixed and immovable annual taxes were to be made good! In what state would the British empire now be if we were subjected to the action of similar causes of ruin? A vast and unwieldy dominion exposed on every side to the incursions of barbarous and hostile nations daily increasing in numbers and augmenting in military skill; a fixed taxation for which the whole free inhabitants of every municipality were jointly and severally responsible to meet the increasing military establishment required by these perils; a declining and at length extinct agriculture in the central provinces of the empire owing to the deluge of cheap grain from its fertile extremities wafted over the waters of the Mediterranean; multitudes of turbulent freemen in cities kept quiet by daily distribution of provisions at the public expense from the imperial granaries; and a half or two-thirds of the whole population in a state of slavery--neither bearing any share of the public burdens nor adding to the strength of the military array of the empire