In 1975, I took a college course in psychology. The professor invited a gay man to speak to the class. He explained to us, "I'm just like you, only I prefer to have sex with men instead of women." No one objected or protested. What did we know? The thesis seemed plausible then, and today most people regard it as axiomatic.

The gay agenda is to convince the heterosexual majority that there are no appreciable differences between homosexuals and heterosexuals. We are to believe that sexual preference is merely a personal choice with no broader ramifications for society. The choice of a sexual partner or partners is supposed to be as innocuous as choosing a flavor of ice cream. The inescapable corollary is that any biases against homosexuality are necessarily irrational.

Attitudes toward homosexuality have shifted dramatically since the 1970s. In 1977, forty-three percent of the population thought homosexual relations between consenting adults should be criminalized. By 2015, this number had dropped to twenty-eight percent. As recently as 1996, only twenty-eight percent of poll respondents endorsed gay marriage. By 2015, the number had risen to fifty-eight percent. In Obergefell v. Hodges (2015), the US Supreme Court declared that gay marriage is a Constitutional right.

The gay agenda is now a fait accompli. How was it sold to the American people? In three ways. First, by control of language. Second, by media propaganda. Third, by relying upon the fact that ignorance is the normal human condition. Most people do not have a clue as to what homosexuals do or what the medical consequences of these practices are.

The most significant tool for promoting the gay agenda was the introduction of the word "homophobia." A phobia is an irrational fear. Thus the use of the term homophobia automatically implies that any aversion or objection to any facet of homosexuality is irrational. The beauty of this is that it removes the burden of argument. The speaker or writer who uses this term has presumed what needs to be demonstrated. Control of language is control of thought.

Nothing illustrates gay propaganda better than the film American Beauty (1999), a movie written and produced by gay men. The Oscar-winning film portrays two heterosexual couples, both of whom have dysfunctional marriages. The lead character, Lester Burnham, is married to a cold, faithless, and selfish realtor preoccupied with maintaining a proper image. Deeply dissatisfied with a life devoid of meaning, the forty-two-old Burnham resigns the position that he has held for the last fourteen years. Realizing that the time at which he was happiest in his life was when he worked at a fast-food restaurant during high school, Burnham finds work at a burger-and-fries joint. At one point in the film, Burnham seems to be on the verge of making an emotional breakthrough with his spouse. But the moment is spoiled when his wife refuses to make love on the living room sofa because it might leave a stain.

The other couple is even worse. The father is a retired Marine, a homophobic martinet who collects Nazi memorabilia and beats his wife and son. As the movie unfolds, we find that the Marine's homophobia springs from his own suppressed and latent homosexuality. The only happy people in the entire film are a gay couple that live across the street. They are well-adjusted, smart, and funny. Invariably, every depiction of gay people in major American media today is unfailingly positive.

The message conveyed by American Beauty is clear. The conventional heterosexual lifestyle and bourgeoisie family that was extolled by previous generations as the epitome of the good life is dysfunctional. Conservatives harbor secret fascist fantasies. They are wife beaters and child abusers. These anti-social derangements spring from the suppression of their own latent homosexual desires. Homosexuality is not merely acceptable, it is superior. If we would all just embrace our inner queer, the world would be a beautiful place.

American Beauty is a ridiculous caricature. But it's not so preposterous as Bambi (1942). People will believe what they see and accept what they are told, no matter how much it contradicts reality. It is impossible to write a history of human error because the subject is inexhaustible. Last Halloween night, a woman had her hand nearly bitten off after she broke into an Omaha zoo to pet a tiger. Nor is her case unique. Exposure to endless movies featuring cute talking animals has convinced a large segment of our population that tigers and lions are nothing more than oversized pussy cats, begging to be stroked and loved. If dangerous animals can be turned into cute pets, homosexuals can certainly be rendered harmless.

Decades of pro-gay indoctrination have produced radical changes in the way that Americans view homosexuality. One of the most startling numbers to come from a 2015 poll is the fact that people estimate the percentage of homosexuals in the population to be 23 percent. This astonishing number is at least ten times too high. A 2013 survey by the CDC found that a mere 1.6 percent of the population is exclusively gay or lesbian. Why is this important? Because boosting their apparent numbers elevates homosexuals from a freakish minority to the mainstream.

Thus we have come in a short period of forty years from regarding homosexuality as a criminal and immoral activity to one that is not only acceptable, but a lifestyle worth celebrating. Progressives view the gay agenda as the inevitable outcome of the moral evolution of the human race. In 2003, Canadian Prime Minister Jean Chretien bolstered his endorsement of gay marriage by explaining that "you have to look at history as an evolution of society." Acceptance of homosexuality as normal and healthy is viewed as akin to the abolition of torture, slavery, and bear-baiting. It's another milestone in a grand morality play featuring the inevitable triumph of reason and enlightenment over superstition and prejudice.

There's just one problem with the gay agenda: it's based on a lie. Homosexuals are not like heterosexuals, nor is the practice of homosexuality innocuous. The single largest problem for the gay agenda is medical science. In 2014, the CDC found that men-who-have-sex-with-men (MSM), about 1 percent of the population, accounted for 83 percent of syphilis cases in the U.S. Syphilis, a disease that was once on the verge of eradication, is spreading like wildfire. According to the CDC, syphilis rates "are increasing at an alarming rate." The statistics for AIDS are similar. In 2010, MSM were responsible for 63 percent of new AIDS cases in the US. The rate of anal cancer among MSM is seventeen times higher than among heterosexuals. It is alarming that the gay community exhibits no restraint and cannot be self-policing. Even school children know about condoms, yet venereal diseases rage unchecked through the population of gay men. A recent report in the medical literature found that infection rates for both gonorrhea and chlamydia are increasing among MSM.

The fact that about two-thirds of syphilis and AIDS cases occur amongst one percent of the population tells us something that is immediate and unambiguous: that homosexuality is not an innocuous choice. What gay men do behind closed doors is fundamentally different from what heterosexuals usually do in their bedrooms. It's also more dangerous. In 1975, when that young man appeared before my psychology class, and told us in all apparent sincerity, "I'm just like you," he was lying.

Statistical data on syphilis and AIDS are just the tip of the proverbial iceberg. The CDC warns us that "many cases of chlamydia, gonorrhea, and syphilis continue to go undiagnosed and unreported." Other STDS, including, human papillomavirus, herpes, and trichomoniasis, "are not routinely reported." And now we have a new horror: a virulent strain of meningitis which strikes suddenly and can kill in a few hours. The Family Research Council describes the sexual practices of homosexuals as "a medical horror story." Of course, the Family Research Council is a conservative advocacy organization. Nevertheless, their claims are backed up by references to the medical literature. Every thesis has to be evaluated on its intrinsic merits, not the aims and objectives of its advocates.

Hypocrisy bothers me. Many of the same people who are enthusiastic about the gay agenda will denounce people who object to mandatory vaccinations. They remind us that vaccinations achieve the common good of reducing disease. But they won't accept that restricting the practice of homosexuality achieves the same end. If you don't accept climate alarmism, you're called a denier of science. But what medical science says about homosexuality is ignored or derided as homophobic propaganda. We are informed, endlessly, of the costs of gun violence, cigarette smoking, and obesity. What is the cost of homosexuality? How much does it cost to treat syphilis, AIDS, and a whole host of other diseases? What cost will we bear for the reemergence of syphilis, a disease that was almost eradicated? Neither are these plagues limited to gays. Bisexual men spread them into the heterosexual population.

I want to anticipate and answer the criticism that venereal diseases also occur among, and are spread by, heterosexuals. Yes, it's true. Every disease that is commonplace among homosexuals also occurs among heterosexuals. Every dangerous or questionable practice engaged in by homosexuals is also found in the heterosexual population. Granting these facts, there are two reasons the argument fails. First, the primary difference is a matter of degree. When 1 percent of the population gives rise to 83 percent of the syphilis cases, we're talking about a profound difference. Second, heterosexual sex must be tolerated because it's necessary for the propagation of the human race. In contrast, homosexuality is completely sterile and practiced only for personal gratification and hedonistic pleasure.

A lot of people will misunderstand what I am trying to accomplish with this essay. I'm not arguing that homosexuality is unnatural. The word "natural" is hopelessly ambiguous, and there are lots of "natural" things that most people would regard as bad. Examples include murder and the bubonic plague. My personal opinion is that homosexuality is usually ingrained, and not a matter of choice. I am certainly not advocating the persecution of gay people. I favor toleration of people who are different from the majority. I'm not advocating anything other than open discussion. I wrote this essay because I object to having a massive fraud foisted upon me. The gay agenda is based upon a lie.

It is a medical fact that the practice of homosexuality tends to promote the spread of disease. If you don't like or accept that fact, it's just too bad. As the saying goes, you're entitled to your own opinion, but you're not entitled to your own facts. There is a logical and intelligible argument to be made for restricting and discouraging homosexuality that is not based upon religion but medical science. The moral opprobrium attached to homosexuality by our ancestors was not based on irrational prejudice but sound reasoning. Homosexuality ought to be tolerated, not celebrated.

Dr. Deming is professor of arts and sciences at the University of Oklahoma, and the author of Black & White:  Politically Incorrect Essays on Politics, Culture, Science, Religion, Energy and Environment (CreateSpace, 2011).