There is no evidence that "Cleanliness is next to godliness" has any ancient Hebrew origins. First English reference appears to be circa 1600. Google it.

Ancient and Rabbnic Jewish thought made all sorts of distinctions between "clean/unclean" and "pure/impure." Rabbinic thought understood "clean" and "pure" as spiritual categories, but I read the ancient texts as being less fastidious and less dualistic. Cleanliness was both a physical and spiritual concept, and the distinction between physical and spiritual was itself minimally important. I rather prefer that older biblical view myself. It is closer to the nature religions of the east.

As a practical matter Jewish women in the middle ages would bathe at least monthly in preparation for "ritual cleansing" in the mikva (ritual bath.) The mikva was also used regularly by some men, sometimes on a weekly basis, and would require bathing of some kind before immersion. In these cases we can observe a distinction between physical and "ritual" (or spiritual) cleanliness... the one being the predecessor to the other... but neither being wholly unconnected in practice.

So while Christianity, we may conjecture, was busy disregarding the body on account of its relatively extreme "spiritualism" (focussed on soul salvation, already living in its own mind with one step in the next world... "after history"), in contrast Rabbinic Judaism of the middle ages was only at most pulled slightly in that direction by the Christian cultural milieu but remained more in touch with the this worldly physicality of its roots, unwilling to decouple physical cleanliness from spiritual "cleanliness." Plain old cleanliness continued to matter as a religious issue to Rabbinic Jews, perhaps in contrast to the views of Christian neighbors.

In a modern 20th and 21st century context, I hypothesize a relationship between the density of settlement and its associated frequency of close human contacts... and the importance of cleanliness as a social marker of status. I suspect that cleanliness is one of many markers of social status that we deploy... evidence of self care, evidence of time to engage in self care.

As the father of a 10 year old boy I wonder whether his aversion to cleaning his hands may not be "the body's wisdom" in action ensuring, against the efforts of his parents, that he ingest enough microbes and the like to stimulate his immune system and ensure life long health. So, gross as his finger nails may be, I'm tempted to let him eat his food with those filthy fingers on the grounds that if it doesn't kill him maybe it will make him stronger.

In about four years he'll realize that he needs to adopt the social markers of cleanliness if he wants routine social success with teenage girls.

Which those unwashed 17th century folks undoubtedly had. They were playing host to a swarm of nasty itchy blood suckers.

It's a statement of how far we've come in hygiene that no one has mentioned the parasite issue. I can't believe it is healthy to have lice living on you and sucking your blood.

You might convince me that a non-athletic white collar worker doesn't need a daily bath, but who wants to go back to the days of lice-filled itching and scratching discomfort?

Give me soap any day! (Every day)

Interestingly enough, I believe quite strongly that my daughter, adopted at age 8 and a half months from China, is as healthy as she is because she was exposed to so many germs in her orphanage. She is now 8 and a half years, has been sick maybe five times in her whole life, has never had a major infection and has never taken anti-biotics (and not because I am morally against them - I'm not).

If she hadn't been tougher, perhaps she would have not made it - I think the letter writer who indicated that some folks who are now developing asthama and allergies might have died in infancy in previous times may have a point.

I'm very glad that our standards of hygeine are not those of the 17th century. That being said, however, I do agree that many of us are oversanitized (with the exception of our hands, which really can never be too clean.) We launder pants that we've only worn for a few hours in a day. Heaven forbid that we wear ANYTHING (except outerwear) more than once before washing it. We have antibacterial EVERYTHING, and we shower like mad.

Having very thick, long hair, I only wash it about every 4 days or so. Do I tell anybody this? I made that mistake once, and will never do so again. The look of distaste was pretty obvious. But it actually takes that long for even a smidge of oil to show up at the roots. Am I to wash it every day, even though it would hurt it more than it helps, and even though it takes 45 deltoid-busting minutes to dry it, just because of society's image of what's clean? We're so scared to be seen as being "unclean" that we don't use our common sense and ask "Does this actually need to be washed right now?"

Thanks for the good review. Since the 1950s, when I was a young boy, and regardless of the doctrine of the times, I have understood that the immune system needs occasional challenge. Exposure to germs strengthens it, occasional mild sickness can help prevent worse.

For a good fictional parable on the subject, read The Naked Sun, in which the "spacers"--humans descended from space colonists--have eliminated all disease, but, when they come to Earth, must wear elaborate garments and filters because they no longer have immunities.

It may have been mentioned in the book, but in order for the sun to stimulate the production of vitamin D, there are certain oils that must be in and on the skin. If one bathes too often, those oils are washed away. Work up a sweat, then sunbathe. Let the sweat dry, and after a while, wash off.

Cleanliness, as your review points out, is practical. But in this as all things, a certain sensible moderation is to be sought. Don't be afraid to get dirty working, and don't be afraid to get clean. There is a wonderful vitalization that occurs after a shower, which cannot be wholly psychological. However, we do not need deodorants and whitening strips. Wash the hair each day with a simple shampoo (NOT a dandruff fighter--those shampoos cause the very condition they purport to fight). Bathe or shower. Brush and floss. By all means wash the hands regularly. But that's enough.

A healthy human body, cleaned with soap, will not emit offensive armpit odors. In general, if something is not natural, like the current fashion for ultrawhite teeth, it is probably harmful.

Sanitation IS partly spiritual. If you have a cleanliness of behavior, you will probably stay clean physically.

One thing the review (and apparently the book) did not comment on is the relation of dress styles to cleanliness. It is very uncomfortable to sweat in contemporary work clothing. In effect, we pushed cleanliness so far that now it is embodied in our very clothing. This is folly, since it tends to make us less active in order to preserve the status of our garments.

Instead of suits, why can't we wear comfortable clothes to work that we aren't afraid to get dirty?

Cleanliness and effort are a very satisfying cycle. It is satisfying to work hard, and satisfying to wash away the by-products of that effort.