CAESALPINUS, Andrew, one of those great and daring geniuses who, contending with the mists of a dark age, elicit the most brilliant truths on the one hand, whilst they sometimes wander into great absurdities on the other, was born at Arezzo in Tuscany in 1519. Of his family nothing is recorded, nor does he appear to have left any progeny, or to have been ever married. Devoted to the studies of physic and natural philosophy, be attained at length the honour of being physician to Pope Clement VIII., during the chief part of whose pontificate, from 1592 till his own death in 1603, at the age of eighty-four, Caesalpinus lived at Rome, in the highest credit and celebrity; for which, as we trace the circumstances of his history, and inquire into his opinions, it seems at first sight difficult to account. Eminent talents have seldom proved a shield against persecution. On the contrary, by adding fear to its malice, they have generally tended to exasperate its fury. How then could Caesalpinus, a professed Aristotelian, and an open unbeliever of revealed religion, whose opinions nearly approached those of Spinosa, exist in the holy court of Rome, which was then beginning to persecute the immortal Galileo? This mystery will but too readily unravel itself.

Caesalpinus seems to have been furnished with two distinct philosophical intellects, which, like a good and evil genius, directed him by turns. Under the influence of the one he discovered the circulation of the blood, the sexes of plants, and the only true principles of botanical classification; under the guidance of the other he became entangled in the metaphysics of the schools, the dreams of Aristotle, and a philosophic contempt for every thing, good or bad, connected with the nonsense he was obliged publicly to respect. It is scarcely necessary to remind the reader, that, however brilliant the reign of literature and taste in the golden age of Leo X. and the times which immediately succeeded, true science and experimental philosophy were as yet in the cradle. In this respect the time of Caesalpinus was “dark as Erebus,” and the light he struck out was altogether his own.

We have no account of this great man till we find him seated in the botanical chair of the University of Pisa, where also he studied, if he did not teach, anatomy and medicine. His first publication was entitled Speculum Artis Medicae Hypocraticum, in which it were too much to expect he should have released himself from the shackles of his venerable guide; but he has left evident proofs, in a passage often quoted, of his having a clear idea of the circulation of the blood, at least through the lungs. In botany his inquiries were conducted on a more original plan, and their result was one of the most philosophical works in that science, which issued from the press at Florence in 1583, in one volume quarto. The title-page runs thus: De Plantis libri XVI. Andreoe Caesalpini Aretini, Medici clarissimi docüssimique, atque Philosophi celeberrimi ac subtilissimi; yet he appears to have been himself the editor of the work, to which is prefixed, in his own name, an elegant and learned epistle dedicatory to Francis de’ Medici, grand duke of Tuscany. This book, now rarely to be met with, is not only the unacknowledged source froiń which various subsequent writers, and especially Morison, derived their ideas of botanical arrangement; but it was a mine of science to which Linnaeus himself gratefully avowed his obligations. His own copy evinces the great assiduity with Which he studied the book. He has laboured throughout to remedy the defect of which Haller complains, of the want of synonyms; and has subjoined his own generic names to nearly every species. He has particularly indicated those remarkable passages, in pages 13 and 15, where the germination of plants and their sexual distinctions are explained. In the former we trace the first rudiments of a natural classification of plants by the differences in their cotyledons; or, in other words, we find the origin of the natural systems of Linnaeus and Jussieu: in the latter passage we detect the fundamental principle of the Linnaean artificial system. Nor were these merely incidental suggestions of the illustrious author. He has pursued his inquiries to a conclusion on which the existence of botany as a science depends, and which the no less eminent Conrad Gesner detected about the same time, though his ideas respecting it were not then made public. The principle to which we allude is the classification of plants by their parts of fructification alone. This was afterwards extended, by the greatest writers on the subject, as Ray and Tournefort, and more completely by Linnaeus, to the discrimination of their genera by the same parts, more particularly considered and contrasted. To this more extensive conclusion, indeed, the principle of Caesalpinus directly and inevitably leads. He pursued it himself to such a length, as to develop some of the most important characters for generic distinctions, such as the flower being superior or inferior with respect to the fruit; the heart of the seed situated at its summit or base; the seeds, or the cells of the seed vessels, solitary or otherwise; the partitions of certain pericarps parallel or contrary to their valves. Linnaeus remarks that this author, though the first systematical botanist, found out as many natural classes, or orders, as any of bis followers. He did not indeed define well the philosophical limits of genera in the vegetable kingdom, and therefore his work cannot be regularly quoted throughout for generic synonyms. The want of plates of his own, and of references to other authors, render, as we have already hinted, some of his names and descriptions unintelligible. Yet Linnaeus has in manuscript filled up many blanks which he had been obliged to leave in his own Classes Plantarum, where the system of Caesalpinus first assumed a synoptical form. This author might probably have adopted a more clear and methodical mode of arranging and explaining the botanical part of his subject, had he not had in view the vague and desultory manner of Pliny, whom he closely imitates in the materials of his numerous chapters, as well as in his style of description. A small and unimportant Appendix to this work, of nineteen pages, appeared at Rome in 1603, which is of very rare occurrence, but may be found reprinted in Boccone’s Museo di Plante Pare, p. 125.

Caesalpinus printed at Rome, in 1596, a quarto volume of above two hundred pages, entitled De Metallicis, dedicated to Pope Clement VIII. which, like his botanical publications, is now extremely rare. In the philosophy of this work Aristotle is his guide; in its method and composition, Pliny. A prefatory address to the pope declares it to have been undertaken in opposition to a certain treatise on the same subject, which, though written with diligence and elegance, contained many things inconsistent with the principles of philosophy, and subversive of the peripatetic doctrines; and with the author of which, as being excommunicated by the holy church of Rome, no measures were to be kept.

In our author’s Quoestionum Peripateticarum libri quinque, published at Rome in 1603, it appears that he scrupled not to stand forth as an open defender of the Aristotelian philosophy, without any concealment of his own peculiar opinions and hypotheses derived from thence. By these he incurred the charge of atheism, preferred by a physician [7:5:775]named Taurel, who, punning on the name of his antagonist, entitled his book Alpes caesae, hoc est, Andreae Caesalpini monstrosa dogmata discussa et excussa. This attack, however, met with little or no countenance; and the learned Aristotelian died in the course of the year, receiving, no doubt, in the very focus of sanctity itself, the funeral honours due to an orthodox physician of his holiness.

Of the medical publications of Caesalpinus, entitled Praxis Universae Medicinae, and 7+ Medicamentorum Facultatibus, we have had no opportunity of forming an opinion for ourselves. By what is to be gathered from his other writings, his ideas of the medical qualities of plants and fossils seem adopted from ancient writers rather than from any considerable portion of actual experiment. Like other physicians of his time, he was too much occupied in ascertaining the articles of the materia medica, to find leisure for doubt, or for practical inquiry, respecting the truth of their reputed virtues. He did, however, promulgate some original ideas relative to the investigation of the properties of plants by their taste and smell. With botany he was not only theoretically but practically conversant. He left behind him a collection of above 760 dried specimens, one of the earliest upon record, which is said to have come into the hands of Micheli, and therefore is doubtless still preserved in the museum of Dr Targioni Tozzetti at Florence. A catalogue of this venerable herbarium is reported to have been prepared for the press, but we do not find that it ever appeared.

Caesalpinus having been settled at Pisa when the great Galileo first presumed to doubt the infallibility of the Aristotelian philosophy, and, most likely, when that rising character became, at the age of twenty-six, professor of mathematics in the same university, we cannot presume him to have been free from the party-spirit which so disgracefully manifested itself there. He must have concurred in the measures which his own associates, leagued with the ruling powers, thought proper to adopt. The ancient school philosophy, derived from the Peripatetics, whether it was considered as a mere abstract speculation, or whether, as being equally absurd and unintelligible with the orthodox establishment, it did not excite alarm, was, as every body knows, allowed to go on very lovingly with that establishment; nor did it, in general, raise any more suspicion than the heathen mythology, studied and exemplified in the same and other schools. But when a spirit of truth and inquiry arose, when principles and opinions were to be submitted to the tests of reason and experiment, the same fatal results which the preceding age had witnessed in what was called religion, were justly apprehended for what was now with scarcely more propriety denominated philosophy. Hence the papal authority, which had suffered shipwreck in the one case, wanting the wisdom to avoid a similar disgrace in the other, gladly clung for support to any ally. These two celebrated occasions, the divorce of Henry VIII. and the base persecution of Galileo, are almost the only ones in which the authority of the pope has been exerted about any matter that human reason could determine, or that much signified, except to his own immediate dependents, how it might be determined. It is a memorable fact, that his decision was no less just in one case than unjust in the other; yet both proved equally ruinous, the former to his power, the latter to his credit. So hazardous is the exercise of usurped or overstrained authority, and so infallibly, thanks to the Author of all Good, do truth and justice rise, with renovated vigour, from such contests.

By this view of our subject the mystery above alluded to becomes clearly unravelled. Caesalpinus, though a known heretic and infidel, professing to be an obedient son, and even a champion, of the church, tried to rise by the ruin of equally learned and more honest men than himself. On the side on which he was absurd and censurable, and on that side only, he was unjust and unprincipled; nor is such a character uncommon. Where he exercised his unbiassed judgment, and honestly sought for truth, he, like Galileo, enlarged the bounds of human knowledge, and made discoveries which will for ever claim the gratitude and admiration of mankind. (x. x.)