The Perfection of all the Aids consists, as I have already proved, in their mutual Harmony and Correspondence, for without this Agreement, they must be always ineffectual; because the Horse can never work with Exactness and Delicacy, and keep the Proportion and Measure which is inseparable to all Airs, when justly and beautifully executed.

This Maxim being laid down, we shall undertake to demonstrate, that the Aids of the Body contribute, and are even capable of themselves, from the Principles of Geometry, to make us acquire the Union of the Aids of the Hand and Leg; and if so, we shall be obliged to own the Conclusion, that they are to be prefer'd to all the rest.

The Justness of the Aids of the Body depends upon the Seat of the Horseman.—Till he is arrived at the Point of being able to sit down close and firm in his Saddle, so as to be immoveable in it, it would be vain to expect he should be able to manage a Horse; because, besides that he would be incapable of feeling his Motions, he would not be possessed of that Equilibre and Firmness of Seat, which is the Characteristic of a Horseman. I would define the Equilibre to be, when the Horseman sits upon his Twist, directly down and close upon the Saddle, and so firm that nothing can loosen or disturb his Seat; and by Firmness, I express that Grasp or Hold with which he keeps himself on the Horse, without employing any Strength, but trusting entirely to his Ballance, to humour and accompany all the Motions of the Horse.

Nothing but Exercise and Practice can give this Equilibre, and consequently this Hold upon the Horse. In the Beginning, the Fear which almost every Scholar feels, and the Constraint which all his Limbs are under, make him apt to press the Saddle very close with his Thighs and Knees, as he imagines he shall by this Method acquire a firmer Seat; but the very Efforts that he makes to resist the Motions of the Horse, stiffen his Body, and lift him out of the Saddle, so that any rude Motion, or unexpected Shock, would be likely to unhorse him; for from the Moment that he ceases to sit down and quite close to the Saddle, every sudden Jirk and Motion of the Horse attacking him under his Twist, must shove him out of the Saddle.

We will suppose then a Person, the Position of whose Body is just and regular, and who, by being able to sit down perpendicular and full in his Saddle, can feel and unite himself to his Horse so as to accompany all his Motions; let us see then how this Person, from the Motions of his own Body, will be able to accord and unite the Aids or Times of the Hands and Legs.

In order to make your Horse take or go into the Corner of the Manage, you must begin by opening it.

To open a Corner, is to turn the Shoulder before you come to it, in order to make it cover the Ground; and then the Croupe which is turn'd in will not follow the Line of the Shoulders, till they are turn'd and brought upon a strait Line in order to come out of the Corner.—In order to turn the Shoulder to open the Corner, you must carry your Hand to the Right or Left, according to the Hand to which you are to go; and to throw in the Croupe, you must support it with the Leg on that Side to which you carry your Hand.—To make the Shoulders turn and come out of the Corner, you must carry your Hand on the Side opposite to that to which you turned it, in order to go into the Corner; and that the Croupe may pass over the same Ground as the Shoulders, you must support with the Leg on the contrary Side to that with which you aided in order to bring the Haunches in; the Horse never can perform any of these Actions without an entire Agreement of all these Aids, and one single Motion of the Body will be sufficient to unite them all with the utmost Exactness.

In effect, instead of carrying your Hand out, and seconding that Aid with the Leg, turn your Body but imperceptibly towards the Corner, just as if you intended to go into it yourself; your Body then turning to the Right or Left, your Hand, which is one of its Appurtenances, must necessarily turn likewise, and the Leg of the Side on which you turn, will infallibly press against the Horse, and aid him.—If you would come out of the Corner, turn your Body again, your Hand will follow it, and your other Leg approaching the Horse, will put his Croupe into the Corner, in such a manner, that it will follow the Shoulders, and be upon the same Line.—It is by these means that you will be enabled to time the Aids of the Hand and Legs with greater Exactness, than you could do, were you not to move your Body; for how dextrous and ready soever you may be, yet when you only use your Hand and Legs, without letting their Aids proceed from, and be guided by your Body, they can never operate so effectually, and their Action is infinitely less smooth, and not so measured and proportioned, as when it proceeds only from the Motion of the Body.

The same Motion of the Body is likewise necessary in turning entirely to the Right or Left, or to make your Horse go sideways on one Line, or in making the Changes.

If when you make a Change, you perceive the Croupe to be too much in, by turning your Body in, you will drive it out, and the Hand following the Body, determines the Shoulder by means of the outward Rein, which is shorten'd; if the Croupe is too much out, turn your Body out, and this Posture carrying the Hand out, shortens the inner Rein, and confines the Croupe, acting in concert with the outward Leg, which works and approaches the Side of the Horse.—This Aid is by so much better, because if executed with Delicacy, it is imperceptible, and never alarms the Horse; I say, if executed as it ought to be, for we are not talking here of turning the Shoulder, and so falsifying the Posture. In order to make the Hand and Leg work together, it is necessary that the Motion should proceed from the Horseman, which in turning carries with it the rest of the Body insensibly; without this, very far from being assisted by the Ballance of your Body in the Saddle, you would lose it entirely, and together with it the Gracefulness of your Seat; and your Ballance being gone, how can you expect to find any Justness in the Motions of your Horse, since all the Justness and Beauty of his Motions must depend upon the Exactness of your own?

The secret Aids of the Body are such then as serve to prevent, and accompany all the Motions of the Horse. If you will make him go backward, throw back your own Body, your Hand will go with it, and you will make the Horse obey by a single Turn of the Waist.—Would you have him go forward, for this purpose put your Body back, but in a less degree; don't press the Horse's Fore-parts with your Weight, because by leaning a little back you will be able to approach your Legs to his Sides with greater Ease.—If your Horse rises up, bend your Body forward; if he kicks, leaps, or strikes out behind, throw your Body back; if he gallops when he should not, oppose all his Motions, and for this purpose push your Waist forward towards the Pummel of the Saddle, making a Bend or Hollow at the same time in your Loins: In short, do you work your Horse upon great Circles, with the Head in and Croupe out? let your Body then be a Part of the Circle, because this Posture bringing your Hand in, you bring in the Horse's outward Shoulder, over which the inner Shoulder crosses circularly, and your inner Leg being likewise by this Method near your Horse's Side, you leave his Croupe at liberty. I call it becoming a Part of the Circle yourself, when you incline a little the Balance of your Body towards the Center; and this Balance proceeds entirely from the outward Hip, and turning it in.

The Aids of the Body then are those which conduce to make the Horse work with greater Pleasure, and consequently perform his Business with more Grace; if then they are such, as to be capable alone of constituting the Justness of the Airs; if they unite, and make the Hand and Legs work in concert; if they are so fine and subtle, as to be imperceptible, and occasion no visible Motion in the Rider, but the Horse seems to work of himself; if they comprize at the same time, the most established and certain Principles of the Art; if the Body of the Horseman, which is capable of employing them, is of consequence firm without Constraint or Stiffness, and supple without being weak or loose; if these are the Fruits which we derive from them, we must fairly own, that this is the shortest, the most certain, and plainest Method we can follow, in order to form a Horseman.