By far the oldest of races in Equestria - their society had been stabilized for a thousand years in the time of humans - the Houyhnhmn are also the most mysterious, being the closest living relatives to the ancient pony forebears known as horses. This mystery is, of course, no result of laziness on the part of scholars; it is simply that, up until very recently, the Houyhnhmn abjectly refused any contact with the outside world. The Houyhnhmn leadership declared on numerous occasions that any connection with modern day ponies would introduce an “unstable element” to their society, and perhaps lead younger, more impressionable Houyhnhmn to stray from the concept of pure reason for baser ideas such as passion or recklessness. This precedent was set during the time of humans, in the only known addendum to their existing law, an addendum known as the Gulliver Decree.
 
Virtually identical to ancient horses in all respects save intellect, the Houyhnhmn are an austere people by all standards, with only simple straw houses and no personal possessions save for what is utilized in communal activities, such as agriculture and lawmaking. Indeed, even these communal activities tend not to have much fanfare, as each Houyhnhmn takes part in their assigned task, performs it to the required degree, and then leave without further dalliance on the tasks.
 
Any time not spent on the communal maintenance is dedicated to philosophical discussion - a fact which puzzles most Equestrian scholars as Houyhnhmn have secluded themselves from any outside knowledge or influence to create grounds for such debate - or artistic endeavors, which amount to observing the natural world around the Houyhnhmn and copying what is seen.
 
Houyhnhmn law appears to be a largely redundant concept; the laws exist - being mostly concerned with maintaining cleanliness, order, and rational thought - but no lawbreakers have ever been seen. The Houyhnhmn have rudimentary jails for lawbreakers, but these seem to not have been used for centuries. In fact, the lower levels of the jail have been put under lock and key, with nopony allowed to enter or leave. Oddly, tracks continue to lead in and out of that part of the prison, although only half of them seem to lead out of it.
 
What is perhaps most interesting about the Houyhnhmn is that, by all measures, they seem to be the examples of physical and mental perfection. There is never any sickness in Houyhnhmn society, all individuals are of sound mind and body, and their cultural interaction has no degree of strife or conflict. Indeed, any mention of troublemakers or physically frail Houyhnhmn either elicits confusion, or some vague reference to something known as a “bone pit” which is not elaborated on.
 
On the topic of vague references, a continual mystery has been brought up in the latest interactions with the Houyhnhmn: the Yahoo, a being that appears to have been their primary force of pack animal. It is not known what became of the Yahoo, or what lead to their extinction, but it IS known that they were at least bipedal, lived in small holes in the Earth, and had very little in the way of lifespan. In any event, they must have been venerated, as me and my party have been called Yahoos during our time here. Indeed, the Houyhnhmn leadership has decreed that all ponies in their land are to be treated as Yahoos, and that they will personally carry this treatment of ponies to Canterlot, where they will establish a diplomatic station.
 
Suffice it to say, I am thrilled that this expedition has gone so well! We may even be invited as honored Yahoo guests to the feast tonight!
 
-Last known log entry of Professor G.I. Ngersnap, Esq., prior to his party’s disappearance in Houyhnhmn territory.