Paul Jewett of Rowley, Massachusetts, was a working farrier — a horse-doctor and hoof-smith — who in 1806 did something quietly radical for his time: he threw out the European textbooks. In his introduction, printed by A. Stoddard in Hudson, New York, he explained that experience had given him "reasons to differ from most of the European theories, and confine my practice to observation only."

What follows in Part I is a short, almost throwaway passage on choosing breeding stallions. It is one of the earliest English-language statements of what we now call functional conformation:

"Such seed horses should be chosen as are large and well proportioned, straight limbed, moving in a right line, heedless of every thwarting object, of an even persevering temper, with short ears, hair and lively countenance."

Read that again slowly. In a single sentence, a 1806 New England farmer-veterinarian named the four traits that every modern horse-conformation judge, breed registrar, and sport-horse buyer still scores for:

• "Straight limbed, moving in a right line" — what equine vets today call tracking true. A horse whose hooves swing in a straight plane (no paddling, winging, or interfering) develops fewer splints, suspensory injuries, and uneven hoof wear. Modern lameness exams begin with a trot-up on hard ground for exactly this reason.
• "Well proportioned" — body proportions (shoulder angle, back length, hip-to-hock ratio) are the foundation of every breed standard from the Hanoverian Verband to the Jockey Club.
• "Heedless of every thwarting object… even persevering temper" — selecting against spookiness and reactivity. There is now a growing body of behavioral-genetics research suggesting that startle response in horses is heritable, and breeders of police, military, and trail horses select on this trait explicitly.
• "Lively countenance" — what judges today call presence or expression, an old but real proxy for general health and alertness.

What's striking is that Jewett offered this without the elaborate humoral theory European farriers of his era still leaned on. No talk of sanguine vs. phlegmatic temperaments, no astrological timing for breeding, no inherited Hippocratic categories. Just: pick the big, sound, calm one with a kind eye that travels straight.

This is the same checklist a modern pre-purchase exam runs through. A vet trots the horse on a hard surface (gait symmetry), palpates the legs (straight limbed), watches the horse react to a flapping tarp (heedless of thwarting objects), and notes the general bearing (lively countenance). Two hundred and twenty years later, the rubric has been instrumented with flexion tests, ultrasound, and genetic panels — but the headings on the form are Paul Jewett's.