The 17th century philosopher, Thomas Hobbs, once defined the human condition as “poor, nasty, brutish, and short.” He himself lived to age 91. Reaching that age in those days, however, was almost unheard of.

If congress ever faces reality, the legislative retirement age likely will rise. Astounding changes over past years shout out for such a change. Although 65 has become synonymous with retirement for the past couple of generations, when Germany became the first country to adopt a government-sponsored social security system, the retirement age was fixed at 70, not 65. And that was as long ago as 1889.

As recently as the start of the 20th century, poor nutrition and chronic infections made people constantly ill. When examined for pension benefits at the start of the 20th century, nearly one-third of older (60- to 74-year-old) American civil war veterans had chronic diarrhea. More than 75 percent has clinical heart disease. Nearly half had chronic respiratory illness.

In the early 20th century, life was still “nasty and brutish,” according to Steven N. Austad, a biologist and professor at the Barshop Institute for Longevity and Aging Studies at the University of Texas Health Science Center, San Antonio.

What happened to health and human longevity during the 20th century “seems almost miraculous,” he wrote in the Gerontological Society of America publication, “Public Policy and Aging Report.” Between 1900 and 2000, he noted, life expectancy at birth increased by near 30 years, more than it had increased during the previous 200,000 years of human history. For 65 year olds the mortality rate declined by 55 percent during the 20th century.

The proportion of the 65-plus population without any disabilities rose by 1.5 percent a year between 1982 and 2005 with some acceleration more recently. Life expectancy at age 65 went up “nearly five years, or 38 percent between the start of Social Security and the year 2000. More importantly, active life expectancy increased by nearly 60 percent.

In the first half of the century, “enormous strides were made in overcoming the hazards of civilization — food, water, and airborne diseases.” Electric power and refrigeration made food less likely to be contaminated. Water supplies were treated with chlorine, and immunizations against major diseases came into widespread use. By mid-century, antibiotics became a wall against bacterial diseases.

In the later 20th century, medical science invented a host of devices, procedures, and medications to alleviate many of the maladies of old age. Can the rate of health improvement be sustained in coming years? It’s easy to be optimistic that it can. Tools in genomic science will be making more contributions to human health.

Raising the retirement age “would involve many complex and interlocking economic, social and political implications about which” Austad said he didn’t feel qualified to comment. “However, from a purely biological prospective,” he said, “there can be little question that to the extent that the 65-year-old retirement age made sense in 1935, it makes little sense today.”

The average 65 year old today is “healthier than the 65 year old of 75 years ago in almost every way we can measure....So, a reasonable point of departure for a discussion about retirement might be to ask why it shouldn’t be raised to at least 70 now, particularly since the nature of work itself has so dramatically changed.”

National Occupational and Wage Estimates show that fewer than one tenth of current U.S. jobs now require strenuous activity or sharp reflexes. A 70-year-old requirement might be appropriate for many sedentary jobs but not such occupations as, say, firemen. The mandatory retirement age for airline pilots was raised from 60 to 65 five years ago, for instance.

Given the impending financial load now being imposed on the country by the tidal wave of baby boomers, “Gerontologists of all stripes” need to be heard when political decisions are made about any raise in retirement age Austad says.

And certainly more than a few seniors have an opinion on the subject.

Tait Trussell is an old guy and fourth-generation professional journalist who writes extensively about aging issues among a myriad of diverse topics.