TVWW is dedicated to the best that TV can offer, but it's worthwhile, from time to time, to dredge the bottom of the lake, haul up the darkest muck we can find, and examine it under the cleansing light of our internet glare.

Given National Geographic's new season of the bottom-feeding Taboo, it's clear that the little gold rectangle (their logo), which once symbolized the knowledge of the world, also now stands for a meshugganah Pandora's Box of human behavioral disorders...

The network that, in the past, has explored the secrets of the Egyptian pyramids and the wonders of how giant telescopes are made is back this week with a seventh season of Taboo, the show that begins with teasers such as, "Dave has always felt that his right leg never belonged to him, so one day he decided to amputate it... himself." (Tonight's season premiere -- Monday, 10 p.m. ET -- is devoted to "Addictions.")

Would that I were brave enough, like our new amputee Dave, to comply with the urge to cut my head off before watching Taboo...

We're not exploring the migratory patterns of Arctic penguins here, but how far outside society's cultural norms people will go in their taboo lifestyles or their addictions. Or, as we saw recently, Stanley, the Adult Baby from the episode "Fantasy Lives" (repeated Wednesday, May 11, at 5 p.m. ET), shown at top above, who has paraphilic infantilism -- characterized by the desire to wear diapers and be coddled like a baby.

I guess I wasn't looking, but at some point Nat Geo -- for decades, back to its days on broadcast TV as National Geographic Specials, the de facto portal for the American armchair explorer, and unintentional pornographers to dopey eight-year-old boys during library hour -- turned into a weird fusion of a Goth Ripley's Believe It or Not and the electronic equivalent of a circus side show.

The same "Fantasy Lives" show with Stanley the Adult Baby also included a look at Japan's "maid cafes," where women dressed up as prim, subservient anime waitresses -- and where, at a few even more taboo establishments, men did the same thing.

I'm just wondering who it is who needs an in-depth look at a woman who is a plastic surgery addict, increasing her breast size to a K cup? (From this season's episode on "Beauty," repeated Monday, May 9, at 9 p.m. ET, and again Wednesday, May 11, at 6 p.m. ET)

And is there actually an "L" cup??

This is National Geographic, after all, an encyclopedic touchstone. And we do get the occasional credentialed doctor or psychologist explaining to us -- spoiler alert -- these people have psychological or brain disorders that make them do strange things, like sewing a corset into their backs.

Dave has Body Integrity Identity Disorder (BIID,) a rare condition that involves a person who is mentally and physically normal, but experiences a strong desire to amputate a limb.

Do we need to understand how and why transsexuals live, and come to make the hard decisions they face? No doubt, of course. This is a painfully marginalized part of society, and we do need to understand.

But this is a format that marginalizes them even further, and makes questionable entertainment out them.

The Nat Geo press release says, "Taboo will test your boundaries and push beyond your comfort zone. Understand seemingly bizarre and shocking practices from around the world."

The question is, Why? Do we really need a parade of rare behavioral disorders and Indian exterminators that catch and eat rats under one tent?

I suppose we do. Scrolling through the shows from previous seasons, I found pieces on a woman who was having a passionate affair with... The Berlin Wall. (On the National Geographic Channel website, HERE.) And others on autopsies, plates of grilled guinea pig heads, and maggot medical treatments.

Clicking on one season brought me to the Nat Geo online store, and in the recommendation column for the episode offered up titles "I might like," including "Eating With Cannibals" and, yes, "Albino Murderers." (The Albinos are the victims, not the killers.)

Admittedly, this isn't the bulk of Nat Geo programming. But, the day that this particular venerable institution, one that has catalogued the wonders of the world, throws in the electronic towel and says, "Uncle, we give up" -- Tru TV, here we come -- is a dark one.

It's either that, or, they've just plain run out of material.

Nat Geo's fascination with taboo cultural norms, dress-up and inappropriate age relationships should be relegated back where they came from -- a place where prurient interests are free to roam and take as much bandwidth as they desire.

Right after Pretty Little Liars on ABC Family...