I had forgotten origin of this, and thought perhaps other
members might have also.Its use here doesn't seem to conform to definition from AHD/

"One day a person whose breath would easily cloud a mirror, he was so much alive, entered the office of The Rose of Dixie. He was a man about the size of a real-estate agent, with a self-tied tie and a manner that he must have borrowed conjointly from W J. Bryan, Hackenschmidt, and Hetty Green. He was shown into the editor- colonel's pons asinorum. Colonel Telfair rose and began a Prince Albert bow."

pons asinorum

SYLLABICATION: pons as·i·no·rum
PRONUNCIATION: pnz s-nôrm, -nrm
NOUN: A problem that severely tests the ability of an inexperienced person.
ETYMOLOGY: New Latin pns asinrum, bridge of fools (nickname of the Fifth Proposition in the Elements of Euclid, due to its difficulty) : Latin pns, bridge + Latin asinrum, genitive pl. of asinus, ass, fool.

Euclid's Fifth Postulate
If a straight line crossing two straight lines makes the interior angles on the same side less than two right angles, the two straight lines, if extended indefinitely, meet on that side on which are the angles less than the two right angles.

I would appreciate reading a sentence in which 'pons asinorum' had been obviously correctly used. Interesting term. I don'g get the geometrical application as explained, however--I don't see how straight lines would ever come around to re-cross the one that had interesected them--can't see this in my mind's eye. I suppose for me to try to explain this to someone at this moment would be an instance of my crossing that pons asinorum.

Comments from a Fool:

If a straight line crossing two straight lines makes the interior angles on the same side less than two right angles, the two straight lines, if extended indefinitely, meet on that side on which are the angles less than the two right angles.

All that fifth postulate is saying is that if a straight line (let's call it L) crosses two other straight lines (let's call them L1 and L2) it will create four angles with each of them. If those four angles are not all 90° then you will have two acute angles and two obtuse angles for each intersection, L/L1 and L/L2. Now we limit ourselves to the angles on one side of line L, one acute and one obtuse, for each intersection. If the two acute angles (let's call them A and B) on one side of line L are facing each other, then the lines L1 and L2 will intersect on that same side of line B.

See http://www.cut-the-knot.org/triangle/pythpar/Fifth.shtml

Seems intuitively obvious to this Fool

It's my bridge and I'll cross it if I want to.

the picture was worth all those words...

Ah, I see. Thanks, Faldage. Even without going to the link I understand through your words that took me over the bridge of troubled wonderers.

wwh, does this term refer to the problem per se or to the point or mental stage beyond which further understanding or learning is not possible. The use of pons seems to imply the latter. I always thought of this term as an elaborately refined way of describing the more commonly used, 'Peter Principle'. Isn't it a lovely word; I love the associations with the Pons in the brain and an asinine state. Thank you for posting it!

As is to be expected, there is more than one "pons asinorum"

From the Catholic Encyclopedia, about Buridan:
"Buridan was not a theologian. In philosophy he belonged to the Nominalist, or Terminist school of Occam, to which he adhered in spite of reiterated condemnation. He adhered, also, to that peculiar form of scepticism which appeared in Scholastic philosophy at that time, and which arose from the growing sense of the inadequacy of reason to solve the highest problems of thought. In his "Compendium Logicae" he developed at length the art of finding the middle term of a demonstration, and this, in the course of time (it is first mentioned in 1514), came to be known as "The Bridge of Asses", i.e. the bridge by which stupid scholars were enabled to pass from the minor or major, to the middle, term of syllogism.. Still better known is the phrase "Buridan's Ass", which refers to the "case" of a hungry donkey placed between two loads of hay, equal as to quantity and quality and equally distant. The animal so placed, argued the dialectician, could never decide to which load of hay he should turn, and, in consequencs, would die of hunger. The "case" is not found in Buridan's writings (though the problem it proposes is to be found in Aristotle), and may well have been invented by an opponent to show the absurdity of Buridan's doctrine. "

Bill! That's lovely information! Thanks. So, now we have a THIRD meaning for the pons asinorum; one that is the 16th century equivalent of Cliffs notes.

Your mention of Occam's razor reminds me of another such principle called Morgan's Canon. It is a similar kind of reductionism that is used in studies of cognition and animal behaviour. Cautions against ascribing higher mental capability to an animal's response, when the same behaviour could be explained more simply.

"… may well have been invented by an opponent to show the absurdity of Buridan's doctrine. "

Or to show the inherent absurdity of philosophy when faced with real world circumstances.