We speak with pride of our freedom, and yet we are slaves to time; it is time to get up; it is time to shave; it is time to get breakfast; it is time to get a plane; it is time to come here to a lecture; it is time for a manuscript; it is time to pay taxes. We have forgotten there are other kinds of time than sun time and chronologic time-months, years, days, and hours.
Our ordinary clocks and calendars fail us completely as tools for the measurement of astronomical or geologic time.
There is such thing as biologic time, determined by the rate of living, which may be very rapid in one individual and very slow in another. Phylogenetic time is a subdivision of biologic time. There is also psychological time. To illustrate the variations in psychological time: any military aviator knows that ten seconds of combat are the equivalent of ten minutes in apparent duration and intensity of the experience. Everyone of you needs but to contrast an hour spent in a dentist's waiting room with an hour spent in courtship, to appreciate the variability of psychological time. Nevertheless, each interval is still an hour, as measured by that infernal mechanism, the clock. The rate of living at levels lower than the mental (living which goes on below the level of awareness) is similarly variable. The rate of living is affected by use, by disuse, or by abuse. We must remember that disuse is a form of abuse, as we shall see a little later.
Unfortunately, the great majority of us are biologically older than our years. I would like to reverse the proportions and say the majority of us are biologically younger than our years. But I cannot, and remain truthful. It is my clinical impression that the average individual of sixty years is physically nearer what he should be at seventy, because of unnecessary depreciation.
The biologic age of an individual should be the basic criterion for social adjustments related to age, such as when to grant the right of voting, marriage, retirement, and the assumption and removal of privileges and responsibilities. Is it not utterly ridiculous that a man sixty-four years and 364 days is perfectly competent to carry on the immense responsibilities of an important post, and the next day he is too old to carry them? Such arbitrary retirement rules simply do not make sense.
How are we going to measure biologic age? This is an extremely difficult question, because we have to measure various ages, both structural and functional, and to try to average the estimates. Further complicating the problem is the fact that the various functions and structures are of widely differing significance to our total efficiency. Should the thickness and color of the hair or the presence or absence of wrinkles be weighed the same as visual acuity or the reserve strength of the heart?
The measurement of biologic age becomes a very complex and interesting problem, closely paralleling the challenge involved in the measurement of health, because health and the depreciations of age are closely parallel problems. The definition of health in the dictionaries today is sadly inadequate. Knowing that most medical and college textbooks are at least ten years behind the times, and that dictionaries are at least twenty-five years behind the times, we must not anticipate a revision for perhaps another decade. The antiquated definition of health, as it still appears in authoritative tomes, is that health is that state of being existing in the absence of disease. A negative and utterly inadequate definition. To me, health is that state of being in which all the reserve capacities of the organism are at their maximum. It is an ideal state, an abstraction, and, like infinity, unattainable in its perfection, but approachable.