To me, an honest horse is a willing, hardworking horse who will take care of his rider, even if he knows he's capable of getting away with bad behaviour. He won't make cheap shots or surprise you with uncharacteristic behaviour. He will let you know where he stands, and remain steady in his temperament. An honest horse will check in with his rider before he becomes worried about something, as if asking them if it's okay, as opposed to a dishonest horse who will spook with no regard for his rider. A good, honest horse is always great to ride. It's like you're having a respectful conversation with them, as they will let you know what they think but trust your ultimate judgement. They're not to be confused with pushbutton or deadhead horses; they can still have their bad days, but even at their worst, they never resort to low blows like kicking, biting, rearing, bucking, bolting, or any other bad habit or vice.