(b. Cosenza, Italy; 1509; d. Cosenza, 1588)
Telesio was one of the group of sixteenth-century Italian speculators known to scholars as “nature philosophers,” somewhat to the disparagement of other thinkers who dealt with natural philosophy as then understood but who taught in universities. Telesio’s life was relatively uneventful, except for a brief period when he was taken prisoner during the sack of Rome. He was born in Cosenza, near the toe of the Italian boot: and, after schooling elsewhere in Italy, he returned to spend most of his life there. His first training was obtained from his uncle, a capable scholar who taught him Greek as well as Latin. This at once put Telesio into the special category of men who were able to read philosophical or scientific texts from antiquity in the original language and were not forced to depend upon medieval translations or exegesis.
When Telesio arrived at Padua, then, he was able to compare the interpretations of Aristotle or Galen given in his courses with the Greek texts. The Averroist tradition of Aristotelian interpretation did not appeal to him because it was based on Arab sources. Moreover, there is no trace in his writings of any interest in terminist logic or Mertonian physics, as exemplified in the works of “The Calculator” and other Oxford writers, even though these writings had been widely studied in universities of northern Italy during the previous century. Telesio left Padua profoundly dissatisfied with the Aristotelian doctrines presented there. He does not spell out his indictment in detail: in fact, he seldom makes more than passing allusions to contemporary doctrines. When he speaks of “the followers of Aristotle,” he is more often referring to ancient Peripatetics than to his contemporaries.
After leaving Padua, Telesio spent some time in a Benedictine monastery developing his own system. He began to write while staying at Naples under the patronage of the Carafa family (Telesio was himself a nobleman, although an impoverished one). He developed his thought in opposition to that of Aristotle and the Greek medical writers, with some use of the Greek commentators. He is considered an arch anti-Aristotelian, yet his own style of thinking is so much like that of Aristotle that he might almost be thought of as an Aristotelian revisionist. Why, otherwise, should Telesio have thought it necessary to make a pilgrimage in 1563 to Brescia in order to explain his views to Vincenzo Maggi, a teacher renowned for his knowledge of Aristotle in the Greek? Maggi listened attentively to his views for several days, then confessed that he could not find anything contradictory about them. This was presumably a tribute to the thoroughness of Telesio’s grasp of Aristotle–a grasp so firm that even those most conversant with Aristotle in the Greek were not able to challenge his interpretations or his counterarguments.
Reassured by his interview with Maggi, Telesio published the first version of his major work in 1565, under the title De rerum natura iuxta propria principia. The first part of this title, at this late date in the Renaissance, might lead one to expect a presentation of Epicurean physics as found in Lucretius’ great poem of the same title, which had been discovered in the previous century. The expectation would be disappointed, however, for Telesio was not an atomist or a corpuscularian at all. This crucial fact must be kept constantly in mind, for it separates Telesio from other so-called “new philosophers” with whom he was later associated (for instance, by Descartes and Leibniz), who were mainly atomists. The subtitle was intended to repudiate principles imposed upon nature and thus expressed Telesio’s rejection of what in a later century would have been called a priori theorizing.
In the preface Telesio immediately states that sense is the only valid starting point for speculation on nature. This pronouncement has been taken by most scholars as an empiricist manifesto, but such a view is misleading if one does not recognize that Telesio was not essentially interested in methodology: he never commented on the Organon or other logical works. Such epistemology as can be found in his writings occurs in his discussion of the De anima and other biological works. Since he was conversant with Galen, Telesio must have encountered that writer’s logical empiricism, with its insistence upon the equal roles of sense and reason in science. But there is no stress on reasoning in Telesio’s thought: indeed, reasoning is reduced to the detection of similarities among the deliverances of the senses. For this one-sided reliance upon sense alone Telesio was taken to task by another “nature philosopher,” Francesco Patrizzi. (Patrizzi’s criticisms, with Telesio’s rather unconvincing rejoinders, are printed as an appendix in Fiorentino’s book, listed in the bibliography).
At any rate Telesio, to judge from his writings, was certainly no more, and probably far less, of a practicing empiricist than his favorite philosophical target, Aristotle. He did not have a theory of experiment such as some scholars claim to find in the works of his contemporary Zabarella, nor did he make any controlled observations like those of Patrizzi. Nor did Telesio have a sophisticated conception of the importance of measurement. Nor, finally, was he a mechanist, in spite of the fact that he rejected action at a distance as being the result of an “occult” quality and in spite of his insistence upon the role of matter as a principle of nature.
Having learned all this, surely the reader must be asking, “Why, then, should Telesio be of any interest whatever to the historian of modern science?” The answer lies on the way in which he deployed certain Aristotelian concepts so as to achieve a new system of physical explanation, rejecting metaphysical entities that had no explanatory role in physics. Telesio’s arguments are just about as plausible (or implausible, as the case may be) as Aristotle’s, yet they differ drastically in their results. Surely nothing could have been more disturbing to Aristotelians than this!
What, then, are the chief features of Telesio’s scheme? His basic explanatory arsenal consists of two opposing factors, heat and cold, to which must be added a third principle termed materia but not to be identified with Aristotle’s potentiality, at least not officially. “Heat” and “cold” have taken the place of Aristotelian forms. Telesio is quite explicit on this point: He regards “forms” as “snoring”–that is, as otiose and hence dispensable (this may be viewed as one of the earlier attacks on “substantial forms”). Just as “matter” and “form” cannot really be separated in Aristotelian metaphysics, So “heat” and “cold” and “matter” are physically inseparable for Telesio. In general, heat is associated with motion, expansion, light, and life, while cold is associated with immobility, contraction, darkness, and death–although there is considerable wavering as to the precise relationships between these entities.
The following passage (from De rerum natura [1586 edition], 1, 5)sums up Telesio’s scheme: “Three principles ûprincipia] of things altogether must be posited: two active natures ûagentes naturae]. heat and cold, and a bodily bulk ûcorporea moles]....” This “bulk” or “matter” is described as being “inert” and “dead,” all actions or operations being foreign to it. Aristotle had given a somewhat similar account of heat and cold in De generatione et corruptione (at 329b23), where he identifies “the hot” and “the cold,” “the wet” and “the dry” as primary (tangible) qualities. In keeping with Aristotelian texts such as this, heat and cold were called primae activae qualitates by such contemporary Aristotelians as Zabarella. But for Aristotle the active and the passive qualities make up the four elements (fire being a combination of the hot and the dry, and so on), whereas for Telesio wetness and dryness are not primary but derivative. New explanations are thus required for the traditional “media,” water and air.
All of this Telesian doctrine is supposed to rest, as we have seen, on sense–that is, upon observable features of the cosmological landscape. Thus we feel the warmth of the sun and the coldness of the earth. We feel the immobility of the earth (Telesio was no Copernican and, indeed, seems not even to have been acquainted with the heliocentric hypothesis) while we see the sun moving in the sky. As a first crude hypothesis this is perhaps not unpromising–or, any rate, not much less promising than Aristotle’s cosmology. But obviously Telesio will have his hands full to explain, on the basis of his two active principles alone, all sorts of changes shown to us by sense. We might note that in making the sun fiery or “igneous,” Telesio was, unwittingly, helping to contribute to the breakdown of the barrier that Aristotle had set up between celestial and sublunary physics, the breakdown triumphantly announced by Galileo in his Dialogue Concerning the Two Chief World Systems.
Telesio also introduced concepts of space and time that anticipated the absolute space and time of Newtonian physics:
And thus clearly space can be conceded to be different from the bulk of entities . . . and all entities are located in it. . . . Any given thing is in that portion of space in which it is located, and of which it is the place, and which is completely incorporeal, foreign to all action and all operation, being only a certain aptitude for sustaining bodies and nothing else, . . . .thus completely different from everything [De rerum natura, I, 25].
Thus there can be a void (vacuum). Telesio also held that time would continue to flow on even though no motion were observed by man or even existed. He thus broke away from Aristotle’s conception of place as the surface of the containing body and of time as the measure of motion.
In keeping with his general approach, Telesio regarded the soul (or spiritus) as corporeal–having dispensed with “forms” altogether, he obviously could not accept Aristotle’s definition of the soul as “the form of an organic body.” This spirit “derived from the seed,” for which the body’s integument is a container, is distinguished, not very clearly, by Telesio from the soul introduced by God. Sensation, which cannot be the “reception of forms without matter,” as defined by Aristotle, is the “perception of the actions of things and impulsions of air and [the soul’s] own passions and immutations and motions” (De rerum natura, VII, 2). A thoroughly naturalistic ethics is then developed, with virtues being faculties that ensure the conservation and perfection of spirit (ibid. , IX, 4). As we have seen, reasoning is subsidiary to sensation, the deficiencies of which it supplies in situations in which the whole of a thing’s qualities are not directly observable (ibid. , VIII, 3). Telesio’s discussions of virtues and vices, as they are displayed by a self-interested creature pursuing its own conservation, anticipate similar treatments in the seventeenth century (Descartes, Hobbes, Spinoza). All in all, perhaps the most judicious verdict on Telesio’s thought is that it represented “a robust re-thinking of pre-Socratic naturalism” (Eugenio Garin, Storia della filosofia italiana, II [Turin. 1966]. 711).
I. Original Works. During Telesio’s lifetime three eds. of his major work appeared, all under the basic title De rerum natura iuxta propria principia but with contents progressively augmented (Rome, 1565; 2nd ed., Naples, 1570: 3rd ed., Naples, 1586). There is a modern ed., by V. Spampanato, 3 vols. (I. Modena, 1910: II, Genoa, 1913; III, Rome, 1923). No one has as yet made a thorough study of Telesio’s changes from the earlier to the later eds., even though there are copies of the 1570 ed. with corrections in Telesio’s own hand (Naples, Bibl. Naz. XVI E 68), as well as an autograph commentary on the work (Vatican, Cod. Ottob. Lat. 1292). A new and definitive ed. is being prepared by Luigi De Franco (I, Cosenza, 1965). Shorter treatises also exist in MS (for instance, Naples, Bibl Naz. VIII C 29): some were published by Telesio’s disciple Antonio Persio under the title Varii de naturalibus rebus libelli (Venice, 1590). A treatise on lighting has been published by Carlo Delcorno, “II commentario ‘De fulmine’ di Bernardino Telesio,” in Aevum, 41 (1967), 474–506.
II. Secondary Literature. Still the basic secondary work is Francesco Fiorentino, Bernardino Telesio, 2 vols. (Florence, 1872–1874), with an appendix containing previously unpublished material. A bibliography of Telesian scholarship up to 1937 is given in Giovanni Gentile, II pensiero italiano del Rinascimento, 4th ed. (Florence, 1968). 507–522. Of particular interest are the following: Roberto Almagià, “Le dottrine geofisiche di Bernardino Telesio,” in his Scritti geografici (1905–1957) (Rome, 1961), 151–178; Ernst Cassirer, Das Erkenntnisproblem (Berlin, 1906), 212–218; A. Corsano, “La psicologia del Telesio,” in Giornale critico della filosofia italiana, 21 (1940), 5–12; and Luigi Firpo, “Filosofia italiana e controriforma. IV. La proibizione di Telesio,” in Rivista di filosofia, 42 (1951), 30–47, which gives the text of a condemnation of Telesio’s writings at Padua in 1600.
On Telesio’s biology, the most detailed account is Edoardo Zavattari, La visione della vita nel Rinascimen-to (Turin, 1923). On the relation of physics to metaphysics, see Giacomo Soleri, “La metafisica di Bernardino Telesio,” in Rivista di filosofia Neoscolastica, 34 (1942), 338–356. The most complete work in English is Neil van Deusen, Telesio, the First of the Moderns (New York, 1932).
Neal W. Gilbert
Renaissance philosopher devoted to the study of nature; b. Cosenza, Calabria, Italy, 1509; d. there, October 1588. A sincere Catholic, Telesio enjoyed the esteem of several popes, especially Gregory XIII. He purported to interpret nature by following the lead of the senses and blamed the Aristotelians for indulging in idle speculation. Nature, he wrote in De rerum natura, must be studied in itself and its own principles, which are matter, heat, and cold. Matter is the passive and universal substratum of all physical change. It is not pure potency, as Aristotle taught, but something concrete and tangible. Heat is the source of life in plants and animals, and, together with cold, accounts for all natural events. The whole of nature is animated, and all beings are endowed with sensation in varying degrees (panpsychism).
Man is a composite of soul, body, and spirit. The spirit, which he has in common with all animals, is a very subtle material substance emanating from the warm element and generated with the body. The soul, or mens, informs both body and spirit, is created by God, and is immortal. Its operations transcend the sensible world and reach up to the divine.
Telesio, whom Francis bacon calls "the first of the moderns," paved the way for the scientific method of Galileo galilei and set a trend in philosophy that was soon followed by Tommaso campanella, Francis Bacon, and Thomas hobbes. The weakness of his system, which is not free from contradictions, consists in its treating scientific problems with a philosophical method.
Bibliography: f. florentino, Bernardino Telesio …, 2 v. (Florence 1872–74). n. c. van deusen, Telesio, the First of the Moderns (New York 1932); "The Place of Telesio in the History of Philosophy," Philosophical Review 44 (1935) 417–434. n. ab bagnano, Bernardino Telesio (Milan 1941). g. soleri, Telesio (Brescia 1945).
[b. m. bonansea]
The Italian philosopher of nature Bernardino Telesio (1509-1588) was a leader in the Renaissance movement against medieval Aristotelianism.
Bernardino Telesio was born in Cosenza near Naples. He came from a noble family and received his early education in Milan under the instruction of his humanist uncle, Antonio Telesio. He completed his formal education by studying at Rome and then at Padua, where he was awarded his doctor's degree in 1535. The next few years of his life were spent in a monastery. This was only temporary, however, since he married in 1553. Beginning in 1545, he lived primarily in Naples or nearby at Cosenza. He was responsible for the establishment of an academy in Cosenza consecrated to the study of natural philosophy and based on his ideas and methods. Although Telesio did little teaching at this academy, he did have several pupils who continued the foundation after his death, which occurred in Cosenza in October 1588.
Telesio's most important work, in which his chief naturalistic ideas are advanced, is De rerum natura iuxta propria principia. Although the first part of this work was published in 1565, the work was not completed until 1586. In this book Telesio attacked both the method and content of Aristotelian philosophy. The Aristotelians, he felt, relied too much on reason and too little on the senses. Telesio's own emphasis on the use of the senses to reach natural truth led to the conclusion that knowledge is derived from the senses. In his attack on the content of Aristotelian philosophy, Telesio discarded the Aristotelian doctrine of matter and form. In its place, he argued that all things in nature are based on three principles: matter, which is inert and corporeal; the two natural forces of heat and cold, which are incorporeal and active; and the interaction or conflict of these forces, heat and cold, operating on corporeal, inert matter. From the fluctuating degrees of conflict arise the different types of existence. Although others pointed to contradictions in Telesio's thought, he is still an important figure in the transition from the Aristotelian emphasis on reason and the principle of authority to the modern scientists' emphasis on experiment and independent investigation and observation of nature.
The major studies of Telesio are in Italian. In English, an excellent chapter on him is in Paul O. Kristeller, Eight Philosophers of the Italian Renaissance (1964). □
Bernardino Telesio (bĕrnärdē´nō tālā´zyō), 1509–88, Italian philosopher, one of the leaders in the attack on that part of Aristotelian philosophy that had furnished the foundation for scholasticism. With Bruno and Campanella, he opened the way to a new naturalism, deemphasizing theories of metaphysics and urging the importance of scientific knowledge based upon experience and experiment. He was born into a noble family and studied first with a scholarly uncle in Milan. Further study followed at Rome and in Padua. At Naples he lectured and afterward established his Academia Cosentina in the interest of more scientific methods of thought. While he produced many works on science and philosophy, the outstanding achievement is his De natura rerum juxta propria principia [on the nature of things according to their own principles] (1565–86, new ed. 1910–23). In this he regarded matter as a positive reality that has no need to look outside itself for its sufficient explanation. Out of two opposing fundamental forces (the dry-warm and the moist-cold) in conflict, he sought to produce the reason for all forms of life, great and small. These principles, unscientific by modern standards, were derived from early Greek naturalistic philosophy.