Sometimes in the never-ending quest for outdoor adventure, we embrace the challenge that most intimidates us. We aspire to the least probable objective. This is not, as a famous mountaineer once suggested, because it’s there, but because of something within ourselvs that dictates some emotional place where we want to be.

If that doesn’t strike you as the ramblings of a complete fool, try this: Sometimes we are driven by these compulsions to acts which would seem, to any reasonable person, entirely absurd.

Even more confusing: These two things – the great challenge and the height of absurdity – are not always mutually exclusive.

These thoughts occupy my mind as I cling to a tenuous perch on the face of Cathedral Ledge, that imposing, 400-foot cliff towering above the Saco River Valley near North Conway, N.H.

And at the moment, these thoughts make perfect sense to me.

The route I am rock climbing, called Ventilator, would be a bit difficult to describe to someone who has never donned a harness and shoes with sticky rubber soles. The cliff face here conspicuously lacks any holds for fingers to wrap securely around. It has no cracks into which hands might jam confidently, only minuscule bumps on an otherwise blank, slightly less than vertical wall.

Picture a granite face with bad acne.

Ventilator is known, in the vernacular of the vertically compulsive, as a “friction” climb.

To wit: One meticulously selects the most significant acne scars, places the balls of shoes upon them, then stands upon them. With palms against the wall for balance – or sometimes fingertips pressed against scant, quarter-inch edges of stone – one walks up something resembling an exterior wall of a bank the way a ballet dancer walks across a stage.

For as much as this route excites people like my companions and I, the reasonable non-climber would see nothing enticing about it. Therefore, by a “reasonable person” yardstick, we have tiptoed in the realm of the absurd.

My climbing partner offers some encouragement from a wide ledge below me. “Nice going, Mike,” Tim Kemple calls up to me.

Tim is 14 years old, a high school freshman. He tells me he weighs 110 pounds, though I suspect he wrapped a big, wet towel around himself, and maybe grabbed his math and history books, before stepping on the scale. And Tim climbs routes that make my tendons ache to merely comtemplate.

Tim fell in with this circle of questionalbe role models with whom I occasionally climb when he met two of them by chance this summer, while climbing in Texas. Despite his impressionable age, he might have taken accurate measure of these two – and maintained an appropriate distance – after they decided that he resembles an MTV character and bestowed upon him the unflattering nickname, “Dog Boy.”

Another friend, Bill Mistretta, chimes in with some encouragement. Bill is climbing a route to my left with two other occasional climbing companions.

I choose each move with the thoughtful deliberation of a chess player. Minutes churn by, yet I have advanced just a few feet. Each time I shift my weight onto another dubious foothold, it occurs to me how very little prevents my 160 pounds from succumbing to the practical logic of gravity.

Should a foot slip, I would not pop off spectacularly into thin air so much as slide undramatically down over abrasive stone – remember the term “friction” climb – until my gear, rope and Tim’s belay caught me. This image accelerates my pulse despite my torrid pace; it keeps my head buzzing.

But when I finish the route, that buzzing melts into a feeling of elation at having climbed it. Yes, I know – unbashed absurdity.

Now about halfway up Cathedral, the five of us scramble to the base of another route, aptly named The Book of Solemnity: two towering granite walls merged together like the facing pages of a book held open in a lap.

Not 30 feet up the first section of friction climbing, a foot slips and I slide a few feet before Tim’s belay stops me. A small, bright rasberry rises on one of my elbows.

Near the top of the route, that adrenal overdrive kicks in again.

The “open book” ends at a shelf of rock projecting out over my head. I pause, trying to puzzle out how to get around this obstruction. I’m up high now, and the perspective has a way of gnawing at one’s confidence.

Tim calls out suggestions. I glance down at him, reclined on a capacious ledge some 80 feet beneath me. Another couple hundred feet beneath him lies flat earth.

Only the inside edges of my shoes make contact with the rock, creating some minimal friction. I gingerly reach my left hand out over the bulge above my head, groping blindly. All my pores suddenly open up in a flood of anxiety.

Then I find a deep edge and latch onto it, step left, lock both hands onto it. My pores seal up again, and I’m awash in a eurphoria I could not explain to a reasonable person. It would sound absurd.

Michael Lanza is a syndicated columnist. Questions, letters and column ideas can be sent to 9 South St., Suite 2, Lebanon, N.H. 03766.