Bernardino Telesio (1509 – 1588) was an Italian philosopher and natural scientist. Opposing the Aristotelianism which characterized medieval scholarship, he developed an empirical approach to natural philosophy and treated it as a separate field of study from theology and metaphysics. He abandoned the purely intellectual sphere and proposed an inquiry into the data given by the senses, from which he held that all true knowledge really comes. Telesio avoided Aristotle’s separation of the corruptible earth from the eternal heavens and regarded all matter as affected by two opposing elements of force: heat, which expands, and cold, which contracts. His system was a forerunner of subsequent empiricism, scientific and philosophical, and his famous work, De Rerum Natura Iuxta Propria Principia (On the Nature of Things according to their Own Principles), marked the period of transition from Aristotelianism to modern thought. Telesio inspired Tommaso Campanella and Thomas Hobbes, and sowed the seeds of the scientific method employed by Bruno, Bacon and Descartes. His anti-Aristotelianism aroused the anger of the Roman Catholic Church, and a short time after his death in 1588, his books were condemned and placed on the Index.
Bernardino Telesio was born of noble parentage at Cosenza, a town in Calabria, a region of Southern Italy. He was educated at Milan by his uncle, Antonio, himself a scholar and an eminent poet, and afterwards at Rome and Padua. His studies included the Renaissance curriculum of classics, science, and philosophy. Telesio began an attack upon the medieval Aristotelianism which then flourished in Padua and Bologna. Resigning to his brother the archbishopric of Cosenza, offered to him by Pope Pius IV, he began to lecture at Naples and finally founded the academy of Cosenza. In 1563, or perhaps two years later, appeared his great work De Rerum Natura Iuxta Propria Principia (On the Nature of Things according to their Own Principles), which was followed by a large number of scientific and philosophical works of subsidiary importance. The heterodox views which he maintained against Aristotelianism aroused the anger of the Roman Catholic Church, and a short time after his death in 1588, his books were condemned and placed on the Index.
Thought and Works
Telesio was the head of the great South Italian movement which protested against the accepted authority of abstract reason, and sowed the seeds from which sprang the scientific methods of Campanella and Bruno, and of Bacon and Descartes, with their widely divergent results. Telesio developed an empirical approach to natural philosophy, which he regarded as a separate field of study from metaphysics and theology. He abandoned the purely intellectual sphere and proposed an inquiry into the data given by the senses, from which he held that all true knowledge really comes. Instead of postulating matter and form, he based existence on matter and force. He believed that all natural beings were animate, and he avoided the Aristotelian separation of corruptible earth from the eternal heavens. Instead, he regarded all matter as affected by two opposing elements of force: heat, which expands, and cold, which contracts. These two processes accounted for all the diverse forms and types of existence, while the mass on which the force operated remained the same. The whole was harmonized by the concept that each separate thing develops in and for itself in accordance with its own nature, while at the same time its motion benefits the rest. The obvious defects of this theory, (1) that the senses alone cannot apprehend matter itself, (2) that it is not clear how the multiplicity of phenomena could result from these two forces, and (3) that he adduced no evidence to substantiate the existence of these two forces, were pointed out at the time by his pupil, Patrizzi.
His theory of the cold earth at rest and the hot sun in motion was doomed to disproof at the hands of Copernicus, but was at the same time sufficiently coherent to make a great impression on Italian thought. When Telesio went on to explain the relation of mind and matter, he was still more heterodox. Material forces are, by hypothesis, capable of feeling; matter also must have been from the first endowed with consciousness, for consciousness exists, and could not have been developed out of nothing. This led him to a form of hylozoism. The soul is influenced by material conditions; consequently the soul must have a material existence. He further held that all knowledge is sensation ("non ratione sed sensu") and that intelligence is, therefore, an agglomeration of isolated data, given by the senses. He did not, however, succeed in explaining how the senses alone could perceive difference and identity. At the end of his scheme, probably in deference to theological prejudices, he added an element which was utterly alien, namely, a higher impulse, a soul superimposed by God, in virtue of which we strive beyond the world of sense.
Besides De Rerum Natura, he wrote De Somno, De his guae in acre fiunt, De Mari, De Comelis et Circulo Lactea, De usu respirationis, and other works.
The whole system of Telesio showed lacunae in argument, and ignorance of essential facts; nevertheless it was a forerunner of all subsequent empiricism, scientific and philosophical, and marked clearly the period of transition from authority and reason, to experiment and individual responsibility. Telesio became the head of a school in Calabria, and his ideas were widely read and discussed during his own time. Though he opposed Aristotelianism, he drew many ideas from him and tried to transform, rather than undermine, Aristotle’s teachings. Tommaso Campanella followed Telesio in his early writings, and Thomas Hobbes was inspired by him.