Page:The Works of William Harvey (part 2 of 2).djvu/64

 582 ON CONCEPTION.

Timoth'eus, my object being to shake off the sloth of the age we live in, to rouse the intellects of the studious, and, rather than that the diligent investigator of nature should accuse me of indolence, to bid him laugh at my ill-formed and crude notions.

In truth, there is no proposition more magnificent to investi- gate or more useful to ascertain than this: How are all things formed by an " univocal" agent? How does the like ever generate the like ? And this not only in productions of art (for so house builds house, face designs face, and image forms image), but also in things relating to the mind, for mind begets mind, opinion is the source of opinion. Democritus with his atoms, and Eudoxus with his chief good which he placed in pleasure, impregnated Epicurus; the four elements of Empedocles, Aristotle; the doc- trines of the ancient Thebans, Pythagoras and Plato; geometry, Euclid. By this same law the son is born like his parents, and virtues which ennoble and vices which degrade a race are sometimes passed on to descendants through along series of years. Some diseases propagate their kind, as lepra, gout, syphilis, and others. But why do I speak of diseases, when the moles, warts, and cicatrices of the progenitor are sometimes repeated in the descendant after many generations? 1 " Every fourth birth," says Pliny, 2 " the mark of the origin of the Dacian family is repeated on the arm." Why may not the thoughts, opinions, and manners now prevalent, many years hence return again, after an inter- mediate period of neglect ? For the divine mind of the Eter- nal Creator, which is impressed on all things, creates the image of itself in human conceptions.

Having, therefore, overcome some difficulties relating to the subject, I feel a greater desire to enter into it a little more closely, and this with two objects in view first, that what I have hitherto treated cursorily may seem to carry with it a greater weight of probability ; and secondly, to stir up the intellects of the studious to search more deeply into so obscure a subject.

To illustrate the matter, let A stand for the fecundated egg (the " matter" that is of the future chick), which is alterable or

��1 Arist. Hist. Animal, lib. vii, cap. 6 ; et De Gen. Anim. lib. i, cap. 17.

2 Lib. vii, cap. 11.

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