An education should enable everyone to understand that history is a systematic examination of evidence that provides an explanation of past events. This enables the mind to imagine how individual actions and accomplishments of human beings affect our world. Therefore, each generation should benefit from accumulated information.

An examination of documents, letters, diaries and government records reveal human understanding, motivation, intentions and judgment; either directly, or as inferred between the lines. Without such information we would have little reliable evidence of human thought and actions over time.

It would appear that language was a distinctive trait of human beings and was a significant factor in becoming human. Rationality probably evolved along with writing, which allowed humans to recognize that a past existed and that it has influenced the establishment of the present.

Charles Darwin proposed that his travels integrated a historical perspective to the bones of animals he studied; and this in turn had significance, not just to humans, but also provided implications to all creatures.

All the above is particularly important now that the world population has just reached seven billion. The first billion accumulated over an interval of hundreds of thousands of years to the early 1900s.

Then, in the last fifty years, humanity more than doubled to four billion in the 1970s, and then six billion by 2000. And the question must be whether the earth can support seven billion now, and three billion more by the end of this century?

It is time to consider whether more people represent prosperity and progress, such as customers or soldiers. Throughout the past more workers usually depressed wages and increased the economic surplus available to the king, nobility and religious institutions.

This concept made some sense for societies subject to frequent catastrophes such as famines, plagues and wars; but now, human consumption and pollution increasingly adversely affects all life on earth.

Increasingly, with the globalization of work, the incentive of investors and managers is to seek cheap labor or automation; and the effects on poor people remains as it has been for centuries.

However, the world is capable of feeding, sheltering and enriching more people right now. Between 1820, at the beginning of the industrial age, and 2008, when the world economy entered the present recession, economic output increased a dozen times.

During the past several thousand years life expectancy tripled to nearly 70 years; and the number of children per woman worldwide fell from 5 to 2.5. The bad news is that half the world lives on $2 a day or less. Nearly a billion live in slums and are illiterate and undernourished.

Although the world produces two billion tons of grain, less than half is available for humans to consume. Domestic animals get a third and 20 percent goes to industries that produce biofuels, plastics and starches.

Overall, human demands on the earth have increased enormously; particularly our demand for fresh water, two-thirds of which is devoted to agriculture. Climate change will increase supply in some areas, but existing arid areas will likely expand.

During the balance of this century there should be a continuing decline in the number of children per woman, and an increasingly elderly population. A half century ago, for each person over 65 there were more than six children under 15. By 2070, elderly people will outnumber children under 15, and there will be only three people of working age (15 to 64) for each elderly person and the working age will likely be extended past 65.

Significant issues that must be addressed are: greater use of contraceptives, fewer inequalities and greater availability of quality education. All these approaches have value and are mutually reinforcing.

From now on we need measure our growth in prosperity — not the number of people existing on earth, and not by increase in economic output, but how well we satisfy basic human needs.

Our greatest dangers are not the rise of China, Islam or carbon dioxide emissions, but our own faith in the civilization we have inherited from our ancestors.

Dr. Lloyd V. Stover was fortunate, that under the GI Bill, following World War II, he took a course in world history that emphasized Toynbee’s “A Study of History.” It has helped him understand the cycles in which he has been involved. He can be reached at: