Yann Martel, the Booker Prize-winning author of Life of Pi, is sending a book and letter every two weeks to Prime Minister Stephen Harper. Below is Martel's 20th letter, as posted on his website, whatisstephenharperreading.ca. The Citizen will publish his letters every second Monday. Book 20 is Meditations by Marcus Aurelius.

Dear Mr. Harper,

Like you, Marcus Aurelius was a head of government. In AD 161, he became Roman Emperor, the last of the "five good emperors" -- Nerva, Trajan, Hadrian, Antoninus Pius, Marcus Aurelius -- who ruled over 84 years of peace and prosperity that lasted from A.D. 96 to 180, the Roman Empire's golden apogee.

The case of Rome is worth studying. How a small town on a river became the centre of one of the mightiest empires the world has known, eventually dominating thousands of other small towns

on rivers, is a source of many lessons. That Rome was mighty is not to be doubted. The sheer size the empire achieved is breathtaking: from the Firth of Forth to the Euphrates, from the Tagus to the Rhine, spilling over into Northern Africa, for a time the Romans ruled over most of the world known to them. What they didn't rule over wasn't worth having, they felt: they left what was beyond their frontiers to "barbarians."

Another measure of their greatness can be found in the Roman influences that continue to be felt to this day. Rome's local lingo, Latin, became the mother language of most of Europe, and Italian, French, Spanish and Portuguese are still spoken all over the world. (The Germanic hordes beyond the Rhine, meanwhile, have managed to sponsor only one international language, albeit a successful one, English.)

We also owe the Romans our calendar, with its 12-months-and-365 1/4-day years; three days in our week hark back to Roman days -- Moonday, Saturnday and Sunday; and though we now use the Roman number system (i, ii, iii, iv, v, vi ...) only occasionally, we use their 26-letter alphabet constantly.

Despite their power and might, another lesson about the Roman Empire forces itself upon us: how it's all gone. The Romans reigned far and wide for centuries but their empire has vanished entirely. A Roman today is simply someone who lives in Rome, a city that is beautiful because of its clutter of ruins.

Such has been the fate of all empires: the Roman, the Ottoman, the British, the Soviet, to name only a few European empires. Which will be the next empire to fall, the next to rise?

The interest in reading Marcus Aurelius's Meditations lies as much in their content as in the knowledge of who wrote them. European history has got us used to seeing one monarch after another reach the throne for no reason other than direct filial relation, with talent and ability playing no role. Thus the unending line of mediocre personalities -- to put it charitably -- who came to rule and mismanage so many European nations. This was not Marcus Aurelius's route to power. Emperor Antoninus Pius was not his biological father from whom he inherited the throne.

Nor was Marcus Aurelius elected. He was rather selected. Roman emperors did pass on their emperorship to their sons, but this linkage was rarely directly biological. They instead designated their successors by a system that was authoritarian yet flexible: adoption. Marcus Aurelius became emperor as a result of being adopted by the reigning emperor. Each emperor chose whom he wanted as his successor from among the many capable and competing members of Rome's diverse elite class. Members of that class were often related, but they still had to prove themselves if they wanted to move up in the world.

In that, Roman society was much like the modern democracies of today, with their educated, principled elites that seek to perpetuate the system and, with it, themselves. The Rome of then, in some ways, doesn't seem so different from the Ottawa, Washington or London of today. After the alien abyss, frankly, that is much European history, with the Europeans thinking and behaving in ways that we can hardly understand by contemporary standards, it is a surprise to see, nearly 2,000 years ago, a people who thought and fought and squabbled and had principles which they squandered, and so on -- why, a people seemingly just like us. Hence the endless interest of Roman history.

So Marcus Aurelius was a man of great ability selected to be Roman emperor. In other words, he was a politician, and, like you, a busy one; he spent much of his time battling barbarian hordes on the frontiers of the empire. But at the same time, he was a thinking man -- with a penchant for philosophy -- who put his thoughts down on the page. He was a writer.

Emperor Marcus Aurelius was a Stoic and some of his pronouncements are on the gloomy side: "Soon you will have forgotten the world, and soon the world will have forgotten you," is a fairly typical pronouncement of his. There is much made in these meditations on the ephemerality of the body, of fame, of empires, of pretty well everything. Over and over, Marcus Aurelius exhorts himself to higher standards of thinking and behaving. It's bracing, salutary stuff. In many ways, it's the perfect book for you, Mr. Harper. A practical book on thinking, being and acting by a philosopher-king.

It's also not the sort of book one reads right through from page 1 to page 163. It has no continuous narrative or developing argument. The Meditations are rather self-contained musings divided into 12 books, each book divided into numbered points that range in length from a single sentence to a few paragraphs. The book lends itself to being dipped into at random. My suggestion is that each time you open and read it, you put a dot next to the meditations you read. That way, over time, you will read all of them.