Bernardino Telesio, a philosopher and natural scientist…

Bernardino Telesio, a philosopher and natural scientist born of noble Italian parentage, had received a doctorate in 1535 and joined the group of thinkers known as the Accademia Cosentina.

After spending nine years in a monastery, he had lived in Naples and now lives in Cosenza.

The first two books of his major work, De natura juxta propria principia (“On Nature According to Its Own Principles”), had been published in 1565, and the complete edition of nine books appears in 1586.

With this work, Telesio inaugurates the Renaissance empiricist reaction against the practice of reasoning without reference to concrete data.

The central proposition of De natura holds that the only way to understand the things of the natural world is to study nature itself.

This should be done, Telesio asserts, with attention to the physical properties of matter and to the aspects of heat and cold.

He states that matter is not “pure potency,” the concept ascribed to Aristotle, but rather a tangible datum, and his studies of plants and animals have led him to believe that heat is the source of life, a conclusion based on the warmth that he perceives.

Cold complements heat as the other active principle that explains all natural phenomena.

Such a shift to evidence that is available to the senses, in place of the Aristotelian emphasis on conceptual analysis without reference to sense data, will lead Francis Bacon to refer to Telesio as “the first of the moderns.” Despite his emphasis on the study of nature, however, and the relative lack of theological speculation in his works, Telesio also maintains a belief in God, the human soul, and immortality.