his hands to prevent this movement, the horse, between these two forces, must concentrate its native powers, and establish a center of gravity. The result is equilibrium, that is to say, balance. The effects of the legs are effects of impulsion. The effects of the hands are effects of retention. Thence arises the equestrian axiom: Equilibrium is the consequence of effects of opposition.
Suppose, then, that the horse is being maintained in equilibrium between ten degrees of impulsion and ten degrees of opposition. If, now, the impulsion is increased from ten degrees to fifteen, the opposition still remaining at ten, the horse must move forward, with the condition of equilibrium still maintained.
Precisely here lies the difference between the scientific equitation and the lateral or reasoned. The former, to produce movement forward, keeps the same opposition as before, but increases the impulsion. The others cease the opposition, and thereby allow the equilibrium to disappear. These last cannot do otherwise. They are employing the lateral effect only. Therefore, they cannot maintain the effect of opposition against a mechanism which is driving itself forward by a diagonal action. Only the diagonal effect can maintain opposition while the animal moves in diagonal.
The reader will note that it is always from the fore leg involved that the right or left diagonal biped takes its name. This, in my opinion, is a
