Table of Contents
Biological Knowledge Long Before “Biology”
When people in antiquity observed plants, animals, and their own bodies, they did not think in terms of “biology” as a separate science. Yet, they collected an enormous amount of practical knowledge about living beings. This early knowledge formed the foundation on which later biological science could develop.
Two main motives drove this early interest in living things:
- Practical needs: food, medicine, agriculture, animal breeding, and hygiene.
- Worldview and religion: attempts to explain life, death, health, and the order of nature.
Across different cultures, this led to systematic—but not yet fully scientific—ways of dealing with living organisms.
Early High Cultures: Practical Biology
Mesopotamia and Egypt
In the river cultures of the Tigris–Euphrates and the Nile, survival depended on understanding plants, animals, and the human body.
- Agriculture and animal husbandry
- Selection of seeds and domesticated animals.
- Simple breeding decisions: choosing strong cattle, fertile grain, or disease-resistant plants.
- Calendars based on plant growth and animal reproduction cycles.
- Medicine and healing
- Mixtures of plant extracts, animal products, and minerals for wound care, digestive problems, and pain.
- Written recipes on clay tablets (Mesopotamia) or papyrus (Egypt), with lists of effective plants.
- Anatomical observations, especially in Egypt, where mummification produced detailed practical knowledge of organs and their positions.
- Religion and healing
- Diseases often interpreted as punishments or attacks by supernatural beings.
- Rituals and magic formulas were combined with practical remedies.
These cultures showed a strong empirical side (many observations and recipes that “worked”) but did not yet separate natural causes clearly from religious explanations.
India and China
In South and East Asia, ancient traditions developed their own systematic views of living beings, especially in medicine and classification.
- India (Ayurveda)
- Descriptions of hundreds of medicinal plants and their effects on the body.
- Ideas of balance among “body principles” (doshas), which guided diet, lifestyle, and treatments.
- Simple surgical techniques and anatomical observations.
- China (Traditional Chinese Medicine)
- Detailed herbology: catalogues of medicinal plants and animal products.
- The concept of life force (
Qi) and its flow in the body. - Attention to pulse, tongue, and body state as indicators of health.
Although these approaches are not biological science in the modern sense, they show early attempts to systematize knowledge of living organisms and to relate structure (organs, body parts) to function (health, disease).
The Greek Turn: From Practical Knowledge to Natural Philosophy
In the Greek world, starting around the 6th century BCE, thinkers began to ask what life is, how bodies are built, and how natural processes work—without always referring to gods. This is where biological thought starts to move from pure practice toward more systematic explanation.
Early Greek Nature Philosophers
The earliest natural philosophers (e.g. Thales, Anaximander, Empedocles) mainly focused on the nature of matter and the cosmos, but some ideas about living beings emerged:
- Unity of living and non-living: Attempts to explain all phenomena, including life, through a small number of basic elements (e.g. water, four elements).
- Origin of life: Speculation that life arose from moisture, mud, or primal seas.
- First hints of development: Ideas that simple forms might precede more complex ones, though still mixed with myth.
These early approaches lacked systematic observation of actual organisms but were important because they treated life as part of nature, not just as a product of divine intervention.
Hippocratic Medicine: Systematic Observation of the Sick Body
Around the 5th–4th centuries BCE, physicians associated with Hippocrates put medical practice on a more rational basis:
- Clinical observation
- Describing symptoms, course of disease, and patient history.
- Comparing many cases to identify typical patterns.
- Search for natural causes
- Diseases seen as imbalances or disturbances within the body, not primarily as punishments from the gods.
- Influence of diet, environment, and lifestyle emphasized.
- Documentation and case collections
- Medical writings compiled experiences and treatments, allowing later physicians to compare and discuss them.
Though focused on humans, this style of careful observation and recording became a model for later biological work: observe, compare, describe, and look for regularities.
Aristotle: The First Great Naturalist
Aristotle (4th century BCE) is often considered the first major biological thinker in the Western tradition.
Extensive Observation and Description
Aristotle and his students:
- Collected and described many animal species, especially marine animals.
- Performed systematic dissections of animals to study organs and their arrangement.
- Noted similarities and differences between species’ body plans.
He used this material to create:
- Comparative descriptions of anatomy (e.g. hearts, gills vs. lungs).
- Early groupings of animals based on features such as blood (roughly vertebrates vs. invertebrates), egg-laying vs. live-bearing, or mode of life (terrestrial, aquatic, flying).
This was not modern taxonomy, but it was an early attempt at a structured classification of living beings.
Life Processes and Reproduction
Aristotle also attempted to explain:
- Development of embryos (e.g. chick in the egg), by opening eggs at different stages.
- Differences between sexes and reproductive strategies.
- Growth and metabolism in broad terms.
Here, he combined observation with philosophical ideas, for example, assuming a “vital” principle that guided development and form.
Lasting Influence
Aristotle’s works:
- Collected, ordered, and interpreted a vast amount of information on animals.
- Remained authoritative in Europe and the Islamic world for many centuries.
- Illustrated how careful observation, classification, and theory-building can be combined.
Even when many of his details turned out to be wrong, his method of linking observation and general principles shaped later biological thought.
Hellenistic and Roman Contributions
After Aristotle, biological knowledge continued to develop in the Hellenistic kingdoms and later in Rome, with a stronger emphasis on anatomy, pharmacology, and practical medicine.
Anatomy and Physiology in Alexandria
In Hellenistic Alexandria (from the 3rd century BCE):
- Dissections and possibly vivisections (on animals, maybe also on human criminals) were performed.
- Anatomists like Herophilus and Erasistratus distinguished:
- Nerves from blood vessels.
- Different parts of the brain.
- Valves in the heart and major vessels.
They proposed early ideas about:
- The function of nerves (transmission of signals).
- The movement of blood and air (though not yet a correct circulation theory).
These studies contributed to a more detailed structural understanding of the body, even if physiological explanations were still incomplete.
Roman Authors and Practical Compendia
Roman scholars and physicians collected and summarized earlier knowledge:
- Pliny the Elder
- Compiled a vast encyclopedia of plants, animals, and minerals, mixing observation, hearsay, and folklore.
- His work preserved many fragments of earlier naturalistic descriptions.
- Galen (2nd century CE)
- Physician and anatomist whose ideas dominated medicine for over a thousand years.
- Based on animal dissections, he described muscles, nerves, and organs.
- Proposed models of organ function and body fluids.
- Agricultural and veterinary writers
- Described crop management, soil, plant diseases, and breeding of domestic animals.
- Their practical advice reflects accumulated empirical biological knowledge in farming and animal care.
These works show a mix of:
- Careful anatomical and practical observations.
- Strong dependence on established authorities.
- Limited willingness or possibility to systematically test and challenge old ideas.
Beyond the Mediterranean: Preservation and Further Development
While “antiquity” is often summarized with Greek and Roman names, the broader picture includes:
- Continuation and expansion of plant and animal knowledge in India and China.
- Preservation and commentary on Greek works in the Islamic world (from the 8th century onward), which will become relevant for later historical stages.
- Movement and exchange of plant and animal species along trade routes, which also spread practical knowledge about crops, medicines, and diseases.
For the history of biology, an important outcome of this broad ancient period is the accumulation and recording of observations, even when explanations remained speculative or intertwined with religion and philosophy.
Characteristics of Biological Thought in Antiquity
Across cultures, biological ideas in antiquity share some general features that distinguish them from later scientific biology:
- Strong practical orientation
- Focus on healing, agriculture, animal breeding, and everyday survival.
- Observation-based, but unsystematic testing
- Many careful descriptions; little controlled experimentation.
- Mixture of natural and supernatural explanations
- Empirical findings embedded in religious, magical, or philosophical worldviews.
- Beginnings of classification and comparative study
- Attempts to group organisms and compare their structures and ways of life.
- Emergence of written traditions
- Knowledge preserved in texts, allowing later generations to build on or criticize earlier ideas.
These developments did not yet form a unified “science of biology,” but they created the observational, practical, and conceptual groundwork on which later periods—especially the Renaissance and beyond—could develop biology as an explicit, experimental natural science.