The book contains several graphs demonstrating the way that different types of head of state vary. By the criteria Dr. Ludwig chooses, in most of the graphs, (small-d) democrat leaders, such as presidents and prime ministers, always rate the best, with monarchs usually a distant second, with dictators of various sorts off the charts in degrees of disaster. This did not dishearten me, because I have different criteria from Dr. Ludwig about what makes a desirable ruler. The graphs I would have liked to see would have charted numerous subjects which Dr. Ludwig never mentioned: the tax policies, immigration policies, crime rates, government control of education, and degree of regulation of commerce and daily life. With these criteria, I don't have to tell you that European monarchs, at least, would have effortlessly exceeded democrats, under whom all of these things have become an avalanche over the past century.
Another quibble I have is that Dr. Ludwig points out that of all the types of leaders, democrats are the least likely to engage in war. While this is in itself true, I have to point out that the 20th century was the most democratic century in history and also the bloodiest. Before then, while monarchs were constantly declaring war on each other, European wars were mild compared to the horrors that democracies were to unleash upon each other in the 20th. Monarchs may wage more wars, but democrats wage far worse ones.
In his final chapter, Dr. Ludwig tries to find hope for his democratic, probably left-leaning ideals, but admits himself that there isn't much basis for it. He points out the increase in democracies over the past century, but then writes:
Despite these encouraging trends, it is hard to remain confident about their permanence. The problem is that autocratic rule seems to represent the more natural state of affairs among all higher-order primates. The overthrow of fledgling democracies by fascist, authoritarian, and other totalitarian regimes during the past century suggests that representative democracy, a relative parvenu on the historical scene, tends to thrive during stable political times and economic prosperity. When social crises that threaten the livelihood or lives of people arise, they become more prone to lapse to more primitive modes of responding in their selection of leaders and the kinds of government they will tolerate, much as those who learn a second language later in life tend to revert to their native tongue during times of confusion or stress.
One need not agree with all of Dr. Ludwig's premises to see the truth of his conclusions here.