Petitioning a Fourth-Century Emperor: The De Rebus Bellicis

In different societies there are different ways by which new ideas can be circulated to those who will have to decide whether they ought to be implemented. Where the responsibility for putting innovations into practice is spread over a large number of individuals, we like to think that there is a "free market" in ideas as in other commodities: proposals for reforms are advertised in print, and distributed to as wide a section of informed opinion as possible — typically through the letterspage of a quality newspaper: anyone scrutinising the letter-columns of (for example) the London Times will see that this is where a reformer with inventions to market, be they sound or idiosyncratic, hopes to convert the decision-makers.