Anyone who’s been involved in E/C debates has likely heard more than once that “evolution is a religion” (see, for instance, Matt Young’s thread here ). Some opponents suggest that because the theory has been modified somewhat over the years since Darwin’s original proposal, it’s a “theory in crisis,” or assert some other prediction of its imminent demise. Others have stated—correctly, in my opinion—that evolution has as much or more support as the germ theory of disease. So why do people attack evolution, but not the germ theory? Let’s compare the two.
First, a bit of history (and I do mean “a bit;” keep in mind I’m leaving a lot of people, events, and ideas out here). Even in the 19th century, the idea that some form of live contagion served to spread disease was not new. Indeed, the “germ theory” of disease has been around in a raw form for centuries. One of the earliest references to this theory appears in On Agriculture by Marcus Varro in 36 BCE, warning about building near swampy land “…because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases.”
Variations on this theme remained for centuries, but by the 1800s, the main competitor to the idea of some kind of “minute creatures” caused disease was the “miasma theory,” which held that miasmas—noxious atmospheres produced mainly by decaying organic matter—produced disease. This was the dominant theory, and the idea of germs as a root of disease did not gain a high level of support until put forth more formally by Henle in 1840:
The material of contagions is not only an organic but a living one and is indeed endowed with a life of its own, which is, in relation to the diseased body, a parasitic organism.
Though Henle formalized the germ theory of disease in the mid-1800s, there was resistance to the idea, and evidence was lacking. John Snow’s epidemiological studies of cholera were suggestive of an organism rather than a miasma, but Snow did not isolate the organism himself, which could have further cemented the connection.
In the 1860s, Pasteur demonstrated the existence of pathogenic organisms—bacteria and “filterable agents” (viruses) which could cause disease. In the 1880s, Henle’s student, Robert Koch, isolated the causative agents of both tuberculerosis and cholera. More importantly, Koch formalized a way to determine whether an infectious agent was a cause of disease; these have been modified over the years and are known as Koch’s postulates.
- The organism must be present in every case of the disease, but not in healthy individuals.
- The organism must be isolated from the host with the disease and grown in pure culture.
- The specific disease must be reproduced when a pure culture of the organism is inoculated into a healthy susceptible host.
- The organism must be recoverable from the experimentally infected host.
These postulates have been the “gold standard” for determining an infectious cause of disease for the past 125-odd years. However, even from the beginning, they were less than perfect. Using Koch’s postulates to determine the cause of hog cholera, a disease that killed more than 13% of the hogs in the U.S. in several outbreaks in the late 1800s, Daniel Salmon and Theobald Smith determined that the hog cholera bacillus (later named Salmonella cholerae-suis) was the cause of this disease. Koch and Pasteur agreed with them, and indeed, Salmon and Smith had fulfilled Koch’s postulates: they consistently saw the organism in hogs with hog cholera, they isolated it and grew it in pure culture, saw the disease when they infected healthy hogs, and recovered the bacterium. So, how could they be wrong? In 1903, Marion Dorset demonstrated that hog cholera is actually a viral disease, and that the virus had simply been present in the “pure” bacterial cultures. Oops. Thus, an early test of Koch’s postulates—a central principle of the germ theory of disease—failed miserably.
So, Koch and Pasteur were wrong in this case. Does an incorrect statement by the early advocates of an idea disprove the theory? Of course not: it stands or falls on its own merits, regardless of misapplication or incorrect conclusions drawn by using Koch’s postulates. However, there are certainly weaknesses in the theory that merit a second look. I’ll take the postulates one by one:
The organism must be present in every case of the disease, but not in healthy individuals.
Here we run into the problem of the carrier state and sub-clinical infections. A person may show no signs of disease, but may carry the organism on or in their body. Additionally, a disease may be caused by a ubiquitous agent (such as Epstein-Barr virus, which infects ~95% of the population) that causes serious illness relatively rarely. In both cases, the presence of the organism in healthy people makes it more difficult to definitively associate it with a particular disease. Additionally, a disease may develop only after the organism which caused it has been eliminated from the body. Therefore, attempts to culture it will come back negative, resulting in a misleading conclusion that the organism under investigation does not cause the disease in question.
The organism must be isolated from the host with the disease and grown in pure culture.
Here we run into problems of isolation and culture. Not all organisms can be grown in pure culture in the laboratory. Indeed, as I mentioned here, it is estimated that only ~150 out of roughly 400 oral bacteria have ever been isolated; one can imagine how many species of pathogens remain unknown to us in the environment.
The specific disease must be reproduced when a pure culture of the organism is inoculated into a healthy susceptible host.
Here we come to the problem with models. What is a “healthy, susceptible host?” Certainly we can’t go around giving other humans deadly disease, so we most often rely on animal models to replicate the course of infection. However, not all diseases have good animal models, and some pathogens will infect no other species but humans. Additionally, some diseases are not due to an immediate effect of the pathogenic organism, but are due to more distal effects of the organism. For example, the response of the host’s immune system to certain strains of Streptococcus pyogenes can result in rheumatic fever or rheumatic heart disease months or years after the initial infection, and long after the bacterium is cleared from the body. Additionally, this post-infectious outcome seems to occur more frequently in individuals of a certain genotype; so the pathogen genetics plus the host genetics plus the environment (including the presence of other pathogens) all must be taken into consideration when examining development of disease.
The organism must be recoverable from the experimentally infected host.
Assuming we were able to isolate a pure culture in the first place, and have a decent model of infection, re-isolation still isn’t always possible, as many of the problems with initial isolation are also present upon re-isolation. Additionally, the organism may have been cleared by the immune system, or may be present in one organ but not another (for example, the spleen but not the blood, so where samples are taken from may make a difference).
Looking at all of these problems, it might seem that the germ theory of disease isn’t quite as straightforward as many people assume it is. And it’s not—but there are ways to overcome the limitations. Rather than using pure culture methods, we can use molecular diagnostics (such as PCR) to determine the presence of various organisms. Rather than use solely animal models, we can use serological evidence or epidemiological studies to determine a correlation or investigate a cause/effect relationship between an organism and a specific disease in the human population. We can even use these types of studies to investigate infectious causes of chronic diseases, where the infectious exposure may be decades removed from disease development. Yet I’ve not seen many challenges to the “naturalistic” assumptions underlying the GToD as I do with challenges to evolution, nor have I heard the claim that the germ theory is a “religion,” as anti-evolutionists claim about the theory of evolution. Even the religious connections are there; certainly the Bible has been used by some to support the idea that disease is a punishment from God:
So now the LORD is about to strike you, your people, your children, your wives, and all that is yours with a heavy blow. You yourself will be stricken with a severe intestinal disease until it causes your bowels to come out.” Then the LORD stirred up the Philistines and the Arabs, who lived near the Ethiopians, to attack Jehoram. They marched against Judah, broke down its defenses, and carried away everything of value in the royal palace, including his sons and his wives. Only his youngest son, Ahaziah, was spared. It was after this that the LORD struck Jehoram with the severe intestinal disease. In the course of time, at the end of two years, the disease caused his bowels to come out, and he died in agony. His people did not build a great fire to honor him at his funeral as they had done for his ancestors.
(2 Chronicles 21:12-19)
The LORD will strike you with wasting disease, fever, and inflammation, with scorching heat and drought, and with blight and mildew. These devastations will pursue you until you die. The skies above will be as unyielding as bronze, and the earth beneath will be as hard as iron. The LORD will turn your rain into sand and dust, and it will pour down from the sky until you are destroyed. “The LORD will cause you to be defeated by your enemies. You will attack your enemies from one direction, but you will scatter from them in seven! You will be an object of horror to all the kingdoms of the earth. Your dead bodies will be food for the birds and wild animals, and no one will be there to chase them away. “The LORD will afflict you with the boils of Egypt and with tumors, scurvy, and the itch, from which you cannot be cured. The LORD will strike you with madness, blindness, and panic. You will grope around in broad daylight, just like a blind person groping in the darkness, and you will not succeed at anything you do. You will be oppressed and robbed continually, and no one will come to save you.
(Deuteronomy 28:20-29)
I will heap calamities upon them and spend my arrows against them. I will send wasting famine against them, consuming pestilence and deadly plague; I will send against them the fangs of wild beasts, the venom of vipers that glide in the dust. In the street the sword will make them childless; in their homes terror will reign. Young men and young women will perish, infants and gray-haired men.
(Deuteronomy 32:23-25)
Once upon a time, a prevailing view was that God sent plagues as a punishment for sin, and early in the days of the germ theory (like evolutionary theory), some were unsure how it could be reconciled with Holy Scripture. Indeed, there was resistance to the thought of these “germs” as a cause of disease at all, as it took away the aspect of morality that was previously linked to manifestation of many diseases. Disease was often thought to be due to moral failings, and specifically, excesses: too much anger, jealousy, gluttony, or sex, either in an individual, or in the population. Yet as the evidence for the germ theory piled up, religious views were modified to coincide with science: perhaps God was acting through nature, sending these pathogenic organisms instead of causing disease directly. This idea rears itself over and over, and was commonly cited even in the beginning of the HIV epidemic (often referred to as a “gay plague” in the early 1980s, and seen as evidence of God’s wrath). Still, very few people have a problem accepting a naturalistic cause for infectious disease (even if they believe God instigated it).
There are still tons of unanswered questions in the field of infectious disease, and as we learn more, we find it’s not always as simple and straightforward as Koch’s postulates suggest. But this is not a reason to be rid of them, nor to doubt explanatory power of the germ theory of disease. Koch’s postulates are still the gold standard for determining disease causation, and have served us remarkably well through the years. To dismiss the germ theory of disease as a “faulty model” because it’s often more complicated than a simple “one germ–>one disease” correlation is beyond naive, and demonstrates a lack of understanding of the process scientists go through when investigating these issues. And to hold evolution up to a higher standard than the germ theory, or to call it a “religion” but give the germ theory a free pass, when both have many areas of intense and exciting research devoted to filling in gaps in our knowledge, makes no sense to me.
40 Comments
steve · 28 July 2005
This textbook contains material on
the Germ Theory of disease. The Germ
Theory of disease is a theory, not a
fact, and germs cannot be seen with
the naked eye. This material should
be approached with an open mind,
studied carefully, and critically
considered.
Harrison · 28 July 2005
(Sarcasm on) Why stop with questioning the Germ Theory? Let's go back into the 17th Century and ascribe all mental illness to demonic possession! Hey! This is fun! We can close all the mental hospitals and throw all the mentally ill into dungeons. We'll chain them to the walls and call fundies in to pray over them, day and night, until the demons are cast out! And if that doesn't work, well, it must mean that these people are being punished by the Almighty! (Sarcasm off)
Albion · 28 July 2005
I've often asked creationists why they concentrate on evolution while ignoring germ theory. Between the discovery of viruses, the discovery of prions, and the finding that some transmissible diseases are caused by intoxications rather than infections and that some microorganisms cause nontransmissible disease due to immune-system reactions, the germ theory has taken more hits than the theory of evolution in the last century or so.
Somehow creationists don't have the same objection to germ theory as to the theory of evolution, even thought it's had to do some quick changes over time and also deals with biology and hence with life and contradicts some of what scripture says. Most of the excuses go along the lines that evolution is just an extension of abiogenesis, which doesn't exist and therefore evolution doesn't exist. But I have come across creationists who have been honest enough to say that they don't have a problem with germ theory because it's so obvious: one member of a family gets a cold, several others get colds, and there are photos of viruses in textbooks so that shows they exist. And that all the scripture didn't really mean what it said even though it said it.
In other words, germ theory is too obvious for creationists to deny, despite its difficulties (which creationists don't tend to know about on account of the creationist ministries aren't carrying on about them), so therefore it can't be contradicted by scripture and those passages of referring to demons and divine retribution and so on really, when read literally, are clearly allegorical. Or something. It's the same accommodation that's been made for microevolution; if it's too bleedin' obvious for creationists to deny, they claim that not only is it supported by scripture but also that Christians accepted it all along anyway.
Mark · 28 July 2005
So thats the etymology of Salmonella. Interesting post.
harold · 28 July 2005
A really good post on the complexities of studying infectious disease.
Another good question for creationists would be why, under their analysis, there are any "germs" at all. Evolution explains it. What does creationism say? When were infectious microorganisms "designed"? Why?
Slightly off topic - Anticipating those who will claim that this topic "proves atheism", many religions have no problem with science.
http://www.mindandlife.org/hhdl.science_section.html
http://www.ncseweb.org/resources/articles/5025_statements_from_religious_orga_12_19_2002.asp
Flint · 28 July 2005
Basically, the germ theory can be true all it wants, without even suggesting that your grandfather was a gorilla. It's not the process of evolution that annoys the creationists, but rather the implied insult.
The main reason germs aren't in the Bible is because God didn't know about them a few thousand years ago, or if He did, he didn't bother mentioning it. In other words, creation stories are flattering tales to beguile the simpleminded.
Imagine a future scientific discipline of "temporalology" following the invention of a time machine. Now THERE's a discipline that would stand Creationists up on their hind legs. You think we have denial of AIDS, the holocaust, the moon landings, etc., just wait until time travel shows there never was any Jesus. Denial will demolish all current records overnight.
Tara Smith · 28 July 2005
BC · 28 July 2005
"All diseases of Christians are to be ascribed to demons; chiefly do they torment freshly-baptized Christians, yea, even the guiltless new-born infants."
- Augustine, 5th century father of the Christian church
rdog29 · 28 July 2005
A similar history could be given for meteorology, or in this case I'm referring specifically to lightning.
It's my understanding that, prior to Ben Franklin's work, lighnting was widely thought to be a manifestation of God's wrath upon mankind.
When Franklin showed that lightning was electricity on a grand scale, well, so much for the Wrath of God thing.
So why not put Franklin in the same Rogue's Gallery as Darwin? After all, he was instrumental in putting forth a godless, materialistic mechanism for what had previously been the provenance of God.
harold · 28 July 2005
This thread provides an excellent argument that it is inconsistent and hypocritical to reject the theory of evolution on the grounds of so-called "Biblical literalism", while accepting Germ theory.
The point that some people are "offended" by evolution, because of US social attitudes about other primate species which are evolutionarily closely related to us (including the use of terms like "gorilla" and "monkey" as irrational insults), is a good one. This has nothing to do with religion, though. It's a non-religious irrational reason to "reject evolution", even though many of this ilk may claim fundamentalist religious beliefs as well.
It is, of course, unfair to suggest that all religious positions reject evolution, germ theory, or science in general...
http://www.mindandlife.org/hhdl.science_section.html...
http://www.ncseweb.org/resources/articles/5025_statements_fr...
If future people "will" investigate the literal historicity of Jesus, then they "already have"...the paradoxes of time travel...
ThomH · 28 July 2005
re: Ben Franklin. Some people did. But because of the spirit of his age, Franklin was considered a hero of the Enlightenment for that very reason. Turgot's famous quote: "He seized the lightning from the sky and the specter from the tyrants."
Sad that we seem to be moving backwards. Let's put Franklin in the Rogue's Gallery with Darwin, Galileo and many more--the liberators of humankind from ignorance and tyranny.
Flint · 28 July 2005
Ron Zeno · 28 July 2005
Perhaps it's just much more convenient not to attack something that is obviously so beneficial? When one picks scapegoats, best to choose something that won't obviously be missed.
BC · 28 July 2005
The evolution/creation debate is about our origins -- about who we are. This is why its so near-and-dear to everyone's beliefs. This is why people who know nothing about biology feel they need to weigh in on the subject. Many of the people I've talked to who have beliefs in creationism and a loathing of evolution wouldn't even know that antibiotics are useless against viruses -- that's the level of their biological ignorance. So, why do they think they have an intelligent opinion about evolution? Because it touches on origins and it's hyped up be religionists. Are we "created in God's image"? Is the story of original sin true? Or are we descended from apes, and earth was always full of violence and death? Origins is also one of the most important arguments for the existence of God. Evolution allows people to understand human existence without the need to invoke a creator. That's really, really scary to a lot of people. A lot of people need God to be necessary. Hence, they need to villify evolution as "The Lie" (as Ken Ham's book declares).
Rocky · 28 July 2005
RDOG29
My understanding from my fundamentalist friends is, they do, by association, blame all "new order" scientists for their belief of the present day moral state of decay.
Like the past was better somehow.
They all want that nostalgic "ole' day religion".
When I've asked, many times, exactly what historical time-frame that in, the answer is always "before the devil mislead us into our current state of knowledge".
Or, said another way, before what's commonly called the "age of enlightenment".
Come on Dark Ages!
mark · 28 July 2005
Albion · 28 July 2005
And germs can be handily explained away by the Fall.
The sad thing is that even though the real reason why fundamentalists don't attack germ theory is that it doesn't offend them, being easily made consistent with their world view, they refuse to admit that that's their reason. They continue to insist that evolution is bad science, and most fundamentalists don't know or care enough about the science behind germ theory to know that it's no better supported than evolutionary theory.
Albion · 28 July 2005
natural cynic · 28 July 2005
Jim Harrison · 28 July 2005
Germ theory is not problem for even the most traditional of Christians because one can both believe that a disease is caused by germs and that it is the result of divine displeasure. It is a commonplace of anthropology that folk theories of disease leave a place for both natural causes and demons. For that matter, since germs are a necesssary but not a sufficient cause of disease, even modern medicine leaves room for this out. Exposure to germs is like having sex. Disease and pregnancy are not the inevitable outcomes.
BC · 28 July 2005
darwinfinch · 28 July 2005
As noted in various words by many above, and by every creationist post I have ever read here (though not every one ever anywhere), the objection that make ToE the focus of their energies comes out of their endless false pride and vanity: they claim special place next to their god, and of course their own myths describe a similar character.
Sastra · 28 July 2005
It seems that nobody has yet brought up the fact that many forms of alternative medicine do indeed attack germ theory. In the world of altmed, it isn't considered a given at all. Proponents of mind/body/spirit connections often insist that diseases are actually caused by various disruptions in the flow of "life energy." Modern day Vitalists ( which can include New Agers, neopagans, spiritual-but-not-religious and even traditional theists) have been known to argue that germ theory is an unproven component of the materialistic, reductionistic dogma of scientism -- in other words, it's really a "religion."
Creationism is only one kind of pseudoscience, I'm afraid.
steve · 28 July 2005
'Rev Dr' Lenny Flank · 28 July 2005
Carl Hilton Jones · 28 July 2005
EoRaptor · 28 July 2005
EoRaptor · 28 July 2005
BC · 28 July 2005
Jim Harrison · 29 July 2005
For Eorapter. It's not Latin, it's French: Plus ça change, plus c'est le meme chose.
Meanwhile. While I'm also impressed by the differences between chimps and people, I don't see how appealing to a God would explain anything about the transition from something like an ape to something like a man.
The Greeks used to have a saying, "Nothing without Theseus" because the Athenian hero turned up in almost every myth. With the advantage of hindsight we understand why. The resourceful Athenians, who knew a thing or two about soft power, rewrote lots of old stories to insert their national hero into everybody else's stories. If God shows up (uselessly) in the explanations for everything anybody finds remotely remarkable, the reason is similar. The presumption that the God concept is a reasonable hypothesis has been drumed into the public mind at great expense by armies of determined propagandists.
Jim Flannery · 29 July 2005
BC · 29 July 2005
Loren Petrich · 29 July 2005
Kristjan Wager · 29 July 2005
Loren Petrich · 29 July 2005
Kristjan Wager · 29 July 2005
Loren Petrich · 29 July 2005
Kristjan Wager, I got it right -- the Hoerbigerites were not completely successful; one did not have to believe in the Cosmic Ice Theory to be a good Nazi. BTW, in German, the theory's name was originally Glazial-Kosmogonie, but it got renamed Welteislehre or WEL.
My source for this is Patrick Moore's Can You Speak Venusian?
Also check out Martin Gardner's Fads and Fallacies in the Name of Science and Willy Ley's Watchers of the Skies for more on the WEL.
The WEL movement dropped out of sight at the end of WWII, though it revived in the 1950's and 1960's. But if it continues to exist, it has no Internet presence known to me, despite me doing several searches.
BC · 29 July 2005
Its my observation that controversy sometimes exists simply because some group or another doesn't want to accept the implications of the obvious view. This is why creationism is still around, whereas vitalism and demon-caused disease theory is not (or at least isn't common). If you look at it simply from the perspective of "how good is the evidence?" you wind up scratching your head, because the evidence is bad. Looking around the globe, it's clear that acceptance of creationism coincides with religious conservativism (read: the US and the Middle East). It's a sad fact that many people believe what makes them happy and creates the fewest problems for them, even if there is strong counterevidence.
( Speaking of the demon-caused disease theory, there are places in the Middle East where this is taken seriously. There are some fringe groups in the US where this is taken seriously as well. Case in point: "A court in the US state of Wisconsin has heard how an autistic boy died while being held down by worshippers and a priest during an exorcism. Terrance Cottrell, 8, died last year in a service at the Faith Temple Church of the Apostolic Faith in Milwaukee." http://news.bbc.co.uk/2/hi/americas/3877421.stm )
Tara Smith · 29 July 2005
Re: AIDS deniers
The problem there though isn't that they find fault with the germ theory; they simply deny that HIV fulfills Koch's postulates. However, as I described in the first post, there are a number of reasons for that--among them, the carrier state (yes, there are some people who are infected and don't develop clinical disease); inability to isolate virus from sick individuals; different manifestations of disease in different people, etc. What Johnson et al. fail to note is that these problems are found for many more infectious diseases than AIDS, and his beef really shouldn't be with HIV alone, but with the entire theory. But yes, I guess that would be scientific suicide to admit.
Henry J · 29 July 2005
Re "It's not the process of evolution that annoys the creationists, but rather the implied insult."
So being told they're descended from early non-human apes is an insult, but being told that their anatomical, genetic, and biochemical similarities to non-human apes were deliberatedly chosen by a "designer", isn't? I do not see how the first is somehow more insulting than the second.
Henry