Theophrastus
Greek · Fragmentary Texts · Fragment · Philosophy · Ethics
10 works · 8,379 aligned sentences
Birth: 371 BC / Death: 287 BC
Eresos → Athens · botanist · physicist · philosopher
Fragments
This collection of fragments preserves the extensive philosophical and scientific inquiries of Theophrastus, the Peripatetic philosopher who succeeded Aristotle. In the first part, establishing sensation as the starting point of knowledge, the text critically examines the views of Plato and Aristotle concerning the fundamental principles of nature, movement, space, and time. The middle section touches upon logical rules of inference, the ambiguity of propositions, and the nature of discourse, before moving on to ethical and psychological themes such as virtue, pleasure, and the healing power of music. In the latter part, the focus shifts to comparative law, historical anecdotes, and detailed observations of nature—including the behavior of animals, parasitic plants, and the physical properties of water and weather—which are explained through rational analysis rather than myth. Overall, the work reflects a comprehensive effort to understand the order of the cosmos, spanning from abstract metaphysical speculation to minute empirical observation.
Fragmentary Texts196 chunks · §13.1–§190.13,113 aligned sentencesRead →Metaphysics
This work is a philosophical treatise that thoroughly examines the difficult questions surrounding the connection between the first principles grasped by the intellect and the sensible realm of nature. The author begins by questioning how the first principle causes the movement of heavenly bodies, exploring the multiplicity of spheres and the presence of soul within them. He then critically reviews the cosmological theories of earlier philosophers such as the Pythagoreans and Plato, analyzing how reality is divided into matter and form, and whether the first principle must possess a definite limit. Furthermore, he addresses epistemological issues, distinguishing between empirical knowledge derived from sensation and the primary principles grasped only by direct intellectual intuition, thereby pointing out the limits of searching for explanations for everything. Ultimately, the work concludes by defining the scope of teleology in nature, asserting that because the cosmos contains contingency and imperfection, the fundamental task of cosmology is to correctly demarcate the limits of the final cause and the impulse toward the best.
Philosophy7 chunks · §1-7–§31-34697 aligned sentencesRead →On Fatigue
This work is a scientific and medical treatise that systematically investigates the physiological mechanisms, various causes, and treatments of bodily fatigue (kopos). It begins by identifying the physical areas where fatigue occurs and explaining its physiological mechanisms, such as the influx of melted substances (syntema) caused by exercise and excess moisture, while also examining its relation to external factors like insomnia and the environment. The text then demonstrates how seemingly contradictory remedies are physiologically rational, analyzing the impact of bedding, ground hardness, and the differing strains on the legs during uphill and downhill movement. Finally, the discussion explores the effects of arm swings, walking distance, and physical phenomena like nocturnal emission under fatigue, concluding with practical advice on seasonal treatments, dietary habits, and the body's moisture levels.
Philosophy3 chunks · §1.1-1.5–§1.13-1.18361 aligned sentencesRead →On Loss of Consciousness
This work is a medical and philosophical inquiry into the mechanism of the physiological phenomenon of "loss of consciousness" (syncope) through the dynamics of bodily heat. The author defines loss of consciousness fundamentally as the loss of heat or cooling in the vicinity of the respiratory organs. Based on this definition, the text analyzes how physical factors, such as excessive external heat, loss of bodily fluids, or sudden temperature changes after bathing, disrupt the thermal balance of the body. Furthermore, it demonstrates that psychological factors, such as extreme pleasure or pain, also affect bodily heat and contribute to triggering a swoon. Thus, this short treatise systematically elucidates the process through which various internal and external factors disrupt thermal equilibrium and lead to unconsciousness.
Philosophy1 chunks · §1-773 aligned sentencesRead →On Paralysis
This scientific and philosophical treatise aims to elucidate the physiological mechanisms behind the occurrence of paralysis and numbness. The author develops the argument using the concepts of "pneuma" and bodily heat, which were central to ancient natural philosophy and medicine. The text first identifies the primary causes of paralysis and numbness as the cooling of bodily tissues and the resulting abnormalities of pneuma, such as its cooling or deficiency. Furthermore, it explains the specific physical process wherein pressure on the body blocks the flow of blood and pneuma, leading to a temporary or persistent loss of motor and sensory functions. Ultimately, the work attempts to consistently explain visible bodily disorders through the dynamics of invisible pneuma and physical obstruction.
Philosophy1 chunks · §120 aligned sentencesRead →On Stones
This treatise is a scientific and philosophical work that systematically investigates the origins, classifications, and physical and chemical properties of stones, earths, and minerals found in nature. The author begins by tracing the material components of these substances to "water" and "earth," classifying them based on the principles of solidification. The first half details the various reactions of stones to heat—such as melting, bursting, and flammability—along with the unique properties of precious stones used for seals (such as smaragdus and lygurion) and rare materials like pearls and coral. The latter half transitions to practical minerals like touchstones for testing gold, the classification of natural earths and pigments, and the manufacture of synthetic pigments (such as white lead and cinnabar) through human art. Finally, by discussing the properties of gypsum used in construction and bonding, the work demonstrates how natural substances are integrated into practical human life and decorative arts.
Philosophy8 chunks · §2.1–§2.91,125 aligned sentencesRead →On Sweat
This treatise is a scientific and physiological inquiry into the mechanism and properties of human sweat. The author begins by examining the factors behind the components of sweat (such as saltiness and acidity) and its odor, analyzing how these are influenced by age, health condition, bodily parts, and ventilation. It also explores the relationship between internal bodily impurities and skin diseases, as well as the differences in skin and moisture characteristics between children and the elderly. Furthermore, the work analyzes how external and physical factors—such as seasons, temperature, exercise, respiration, and environment (like shade, sunlight, or proximity to fire)—affect perspiration, including the phenomenon where warm water hinders sweating. Finally, it explains the physiological causes of sweating during sleep, anxiety, or when running while clothed, offering a comprehensive overview of the dynamics of heat and moisture within the human body.
Philosophy5 chunks · §1-7–§31-40494 aligned sentencesRead →On Vertigo
This scientific and philosophical treatise investigates the physiological and physical mechanisms behind the phenomenon of vertigo (ilyngos). The author attributes the primary cause of vertigo to the circular motion of air (pneuma) or uneven moisture within the head, as well as the head's voluntary rotation. In the first half, the text explains the varying intensity of vertigo through geometric and visual factors, utilizing concrete examples such as the comparison between raw and boiled eggs, and the tilting of the body when running in a circular path. The second half analyzes how looking down from heights or staring intensely at a single spot agitates and separates the bodily fluids in the brain, incorporating the philosophy of Heraclitus. Ultimately, the work discusses daily bodily factors such as hunger, satiety, and the movement of fluids upon standing up, presenting a comprehensive view of vertigo as a dynamic interaction between vision and bodily fluids.
Philosophy2 chunks · §1-6–§7-13196 aligned sentencesRead →On Weather Signs
This work is an ancient scientific and philosophical treatise that systematically compiles specific signs used to predict weather changes based on natural phenomena and animal behavior. It begins with an introduction outlining the fundamental principles of weather forecasting, emphasizing the importance of observing geographical features and the movements of the sun and moon. The main body is then organized around four primary categories of weather signs: rain, wind, winter storms, and fair weather. The author details an extraordinary range of empirical observations, spanning celestial phenomena, cloud formations, lightning, the behavior of birds, beasts, and insects, and even the flickering of oil lamps and physical bodily changes. Concluding with correlations between seasons and annual weather predictions through plants and animals, the work serves as a practical handbook demonstrating the interconnectedness of the natural world.
Philosophy8 chunks · §1.1-1.8–§4.50-4.571,168 aligned sentencesRead →On Weather Signs
This work is a scientific and philosophical treatise that systematically compiles various natural signs for predicting weather changes such as rain, wind, winter storms, and fair weather. It begins by emphasizing the importance of localized observation and establishing basic principles of weather forecasting based on the movements of celestial bodies like the sun and the moon. The core of the text enumerates specific signs: first for rain, drawing from the behaviors of various animals and birds, cloud formations, and lightning; and then for wind, observing tidal changes, topography, and animal reactions. It further details the precursors of harsh winter cold and storms through the behaviors of mammals and insects, before concluding with the signs of fair weather and long-term seasonal transitions. Through these meticulous listings, the work illustrates the ancient practical approach to understanding the natural world through careful observation of subtle environmental changes.
Philosophy8 chunks · §1.1-1.8–§4.50-4.571,132 aligned sentencesRead →