Part 3 (1/2)

[61] M: pp. 20, 21, 32, 61, 63, 66, 70.

[62] M: p. 59.

[63] M: p. 84.

As we shall see below, the ultimate cause of this internal and superficial life is the motion of the earth, which animation is the expression of the magnetic soul of this sphere.[64] As the life of animals results from the constant working of the heart and arteries,[65] so the daily motion of the earth results in a constant generation of mineral life within the earth. In contrast to Aristotle's[66] making the motion of the heavens the cause of continuous change, Gilbert made that of the earth the remote cause.[67] However, unlike the constant cyclical trans.m.u.tation of substances in Aristotle, there is only generation and decay.

[64] M: pp. 310, 311, 312.

[65] M: p. 338. A somewhat different opinion, although not necessarily inconsistent is expressed on p. 66, where he says the surface is due to the action of the atmosphere, the waters, and the radiations and other influences of heavenly bodies.

[66] Aristotle, _op. cit._ (footnote 45), _De generatione et corruptione_, bk. 2, ch. 10.

[67] M: pp. 311, 334, 338.

Gilbert made a number of successive generalizations in order to arrive at the induction that the form of the loadstone is a microcosmic ”anima” of that of the earth.[68] After comparing the properties of the loadstone and of iron, his first step in this induction was that the two materials, found everywhere,[69] are consanguineous:[70]

”These two a.s.sociated bodies possess the true, strict form of one species, though because of the outwardly different aspect and the inequality of the selfsame innate potency, they have hitherto been held to be different ...” Good iron and good loadstone are more similar than a good and a poor loadstone, or a good and a poor iron ore.[71] Moreover, they have the same potency,[72] for the innate potency of one can be pa.s.sed to the other:[73] ”The stronger invigorates the weaker, not as if it imparted of its own substances or parted with aught of its own strength, nor as if it injected into the other any physical substance; but rather the dormant power of the one is awakened by the other's without expenditure.” In addition, the potency can be pa.s.sed only to the other.[74] Finally they both have the same history:

We see both the finest magnet and iron ore visited as it were by the same ills and diseases, acting in the same way and with the same indications, preserved by the same remedies and protective measures, and so retaining their properties ...

they are both impaired by the action of acrid liquids as though by poison[75] ... each is saved from impairment by being kept in the sc.r.a.pings of the other. [So] ... form, essence and appearance are one.[76]

Any difference between the loadstone proper and the iron proper is due to a difference in the actual power of the magnetic virtue:[77] ”Weak loadstones are those disfigured with dross metallic humors and with foreign earth admixtures, [hence one may conclude] they are further removed from the mother earth and are more degenerate.”

[68] M: pp. xlvii, 309, 328.

[69] M: pp. 18, 20, 44, 46, 69.

[70] M: pp. 59, 61, 63.

[71] M: pp. 60, 63.

[72] M: p. 110.

[73] M: pp. 60, 61.

[74] M: p. 62.

[75] M: p. 63.

[76] M: p. 60.

[77] M: pp. 19, 21, 43, 53, 61, 63, 184.

Gilbert's second induction was that they are ”true and intimate parts of the globe,”[78] that is, that they are piece of the ”materia prima”

of all we see about us. For they ”seem to contain within themselves the potency of the earth's core and of its inmost viscera.”[79]

Whence, in Gilbert's philosophy, the earthy matter of the elements was not pa.s.sive or inert[80] as it was in Aristotle's, but already had the magnetic powers of loadstone. Being endowed with properties, it was, in peripatetic terms, a simple body.

[78] M: p. 61.