And were there any such species or natural kind of animal, it would be hard to make good those six positions of body, which according to the three dimensions are ascribed unto every Animal: that is, _infra_, _supra_, _ante_, _retro_, _dextrosum_, _sinistrosum_: for if (as it is determined) that be the anterior and upper part, wherein the senses are placed, and that the posterior and lower part which is opposite thereunto, there is no inferiour or former part in this Animal; for the senses being placed at both extreams, doth make both ends anterior, which is impossible; the terms being Relative, which mutually subsist, and are not without each other. And therefore this duplicity was ill contrived to place one head at both extreams, and had been more tolerable to have setled three or four at one. And therefore also Poets have been more reasonable then Philosophers, and _Geryon_ or _Cerberus_ less monstrous than _Amphisbæna_. Again, if any such thing there were, it were not to be obtruded by the name of _Amphisbæna_, or as an Animal of one denomination; for properly that Animal is not one, but multiplicious or many, which hath a duplicity or gemination of principal parts. And this doth _Aristotle_ define, when he affirmeth a monster is to be esteemed one or many, according to its principle, which he conceived the heart, whence he derived the original of Nerves, and thereto ascribed many acts which Physitians assign unto the brain: and therefore if it cannot be called one, which hath a duplicity of hearts in his sense, it cannot receive that appellation with a plurality of heads in ours. And this the practice of Christians hath acknowledged, who have baptized these geminous births, and double connascencies with several names, as conceiving in them a distinction of souls, upon the divided execution of their functions; that is, while one wept, the other laughing; while one was silent, the other speaking; while one awaked, the other sleeping; as is declared by three remarkable examples in _Petrarch_, _Vincentius_ and the _Scottish_ History of _Buchanan_.