XXXVII. The school philosophers cannot be ignorant, that these are not definitions, but should rather be termed mere shadows of definitions, which they make use of for want of true ones, to express logically, what definition is, what species, what gender, what difference, and other things appertaining to logical dialect; but is it not clear, that defining a horse by calling him a neighing animal, can give us no better conception of the creature, than may be conveyed to us by the most stupid clown, who would explain the thing more simply, and without school jargon, by telling us that a horse _is an animal that neighs, or is capable of neighing_? Oh! what a penetrating philosophical description is this of the nature of a horse! XXXVIII. If any one, notwithstanding what has been said, should chuse to reply, that nature, as the root of all operations, should be explained according to the order, or habit of those operations; and thus, that a horse is well and physically defined, by the radical order of the act of neighing; if any one, I say, should reply to me in this manner; I apprise him in the first place, that all substantial nature has its absolute being, which is understood to be antecedent to the order of operations, for the first, is supposed to be the cause or reason of the other; that is to say, because such a thing has such a being in nature, from thence is derived the habit or aptness for such operations. I apprise him secondly, that if we should permit nature to be well defined by the precise or characteristic order of operation, this should not be extended to every sort of operation, but should be confined to the primary operation, which marks the foundation of the species; but alas, we are ignorant of what that is. For example, if a man, as is generally thought, is well defined by his rational faculty, or radical power of reasoning; because the being able to reason or reflect, is the principal, or primary operation of man; a horse then should be defined by his radical habit to that act of perception, instinct, or knowledge, which is proper to his species, and distinct from that of all other animals. But who has penetrated what this is? Or who has ever known the innate difference, that there is between the instinct of a horse and a dog? And thus, as it would be ridiculous and absurd to define a man by the radical order of elocution, by saying, that he is an animal who can talk and discourse; because this absurdity would be incurred, on account of the act of elocution being posterior, or secondary to that of reason or reflexion; and it would be much more ridiculous, to define him by the order of his voice, which you describe by some particular name, and to define him in the manner you define a horse, which you call a neighing animal; nor is it less absurd to define a horse by the radical order of his neighing. I apprise him thirdly, that if such definitions are admitted as good