Hippocrates and Galen make no difference betweene a part, a particle, or a place. Galen in the first booke of his method, defineth a Part to be whatsoeuer doeth integrate or accomplish the whole: and in his first book de Elementis, whatsoeuer maketh to the constitution or frame of mans body. For a Part is one of those thinges which the Logicians doe call 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, that is, haue reference or respect vnto another: so a part is said to bee a part of the integrum and whole. In his first booke de vsuparttum, he defineth a Part more accurately thus: It is a body which neither is incompassed with a proper circumscription, nor yet is on euery side ioy∣ned vnto other bodies: for that which is incompassed on euery side cannot be called a Part but a whole. Now whereas the part must helpe to compound the whole, it is necessary it should adheare or cleaue vnto it by a connexion of quantity; wherefore in the whole bo∣dy, a Part hath a true existence, and is indeed ioyned thereto, but in reason deuided there∣from. But both these definitions seeme to me to be too large, comprehending not onely the liuing particles of the body (which are onely true parts because they alone performe actions, and are affected with diseases) but also those that are without life, as haires, nailes, fat, and the marrow of the bones. Fernelius hath left vs a most perfect and absolute defi∣nition of a Part in these wordes: Pars est corpus toti cohaerens, communique vita coniunctum, ad illius functiones vsumque comparatum. A Part is a body cohearing or cleauing to the whole, and ioyned to it in common life, framed for his vse and function. From hence we may gather, that two things are required to accomplish the nature of a Part: First, that it should cleaue vnto the whole, and next, that it should haue some end or vse. The coherence of the part to the whole is by a double connexion, one Mathematicall, another Physicall: the first is a coherence of quantities; for a part of the creature being separated from the whole crea∣ture, cannot bee called a part of that whole, vnlesse it bee equiuocally. The latter con∣nexion is called specificall, and is a vnion of life: for a dead or mortified part, although it haue a coherence with the whole, yet may not be called a part but equiuocally, because it hath not an vniuocall forme with the whole. But because Fernelius in the second booke of his Physiology, hath canuased this definition, and all the minutes thereof very exactly; I will not at this time insist vpon the explication of it, it may be we shall haue fitter opor∣tunity for it hereafter.