This served as a life lesson for the counterculture, most of whom resumed bathing. But now, fifty years later, we – at least those of us in California – are about to receive another such lesson, this one more drastic and widespread.

Years ago, Tom Wolfe published a funny piece dealing with the reappearance during the Summer of Love of diseases never seen in the modern epoch. Wolfe's overall term for these disorders was, if I recall correctly, "The Crud." Doctors were unfamiliar with these conditions and in some cases uncertain as to how to treat them. Some of those children of nature ended up with chronic disorders.

Over the past year or so, AT readers have derived quite a few laughs over what has come to be called the "s‑‑‑ map," a map of the neighborhoods of San Francisco in which the streets are inundated with human waste left by the homeless. (Some commentators assumed that the map was intended as a warning to tourists. But in fact, its creator has recently added a comment asserting that it is intended to "bring attention to the issue of homelessness." Thanks very much.)

This is a remarkable development. Filth-encrusted streets were a pre-modern phenomenon, an aspect of a medieval world that no longer exists in most of the northern hemisphere. Filthy streets were a standard element of urban existence until late in the 19th century. In the U.S., the original Progressive movement (a reform movement, let's remember, with little relationship with postmodern "progressives") made sewage systems a primary goal of its program.

The result was dramatic upgrading of urban life throughout the industrial world, rendering it more pleasant, healthier, and infinitely less lethal.

It was less lethal because the squalid conditions of pre-modern urban streets acted as a breeding ground for a plethora of diseases. The result of these fetid conditions was chronic low-level disorders of the skin and intestinal tract, broken by occasional full-bore epidemics that could carry off large fractions of a city's population.

The prince of these epidemic diseases was cholera. Currently unknown in the industrialized West (most doctors have never seen a case), cholera was a filth-based disease caused by human and animal waste and nothing else. Originating in the Ganges delta, cholera spread across the planet until, in the 19th century, it was a standard feature of urban life. Cholera epidemics were chronic, breaking out wherever sewage mixed with drinking water. Cholera was an oddity among diseases in that it often progressed with no visible symptoms. An individual showing no symptoms at all could suddenly collapse at noon and be dead by sundown.

Cholera still exists in the Third World. According to the WHO, the most recent pandemic broke out of South Asia in 1961 and reached the Americas by the 1990s. "Cholera is now endemic in many countries."

We will also point out that the city of San Francisco is a sanctuary city, or, in the words of the ordinance itself, "a City and County of Refuge." That is, San Francisco has put out the welcome mat for tens of thousands of third-world illegals. The city has made itself a magnet for refugees from countries with no modern sewage systems and no tradition of personal hygiene – the same countries in which the WHO asserts that cholera has become "endemic."

So put these two factors together – streets engulfed in human s‑‑‑ and immigrants from countries overrun with infectious diseases – and what do we get?

We get a blast from the past. We get a taste of urban life in the 18th and 19th centuries. We get a form of terror unwitnessed by any living American.

We get a cholera epidemic.

This will come. It is, by very the nature of things, unavoidable. It is one of those things described by the novelist Robert Heinlein as "two trains on the same track accelerating toward each other." It may well come with the hot weather next summer.

There's no point in asking whether the state of California will be "prepared." Of course it is. There will be plenty of marches and petitions. Donald Trump is available to be blamed. The unicorns and butterflies are ready to chase all the bad things away.

And beyond that, we have diphtheria, typhus, yellowjack, dengue fever...the possibilities are endless.

Ain't liberalism grand?