Biology of Ancient Greece
In ancient Greece and the Hellenistic world, the scholars were interested more in the empiricism. Aristotle was a philosopher of nature's most prolific of the ancient world. Despite his early work rather speculative, it later led research in biology, based on observation. He did not realize experience, but observed that it was the natural reality of each thing in its own environment , although some are artificially controlled.
Although physics and chemistry this method was not considered effective, it was the opposite in zoology and ethology, and the works of Aristotle have a real interest He made countless observations of nature, particularly in habitats and characteristics of plants and animals that lived near him in providing care to the considerable categorize. In all, Aristotle classified it 540 animal species, and dissected about fifty. Aristotle believed in the goals intellectuals, formal causes, which should guide all natural processes.
This theological point of view gave Aristotle a reason for the facts as he observed the expression of a formal model. In noting that "no animal has not, at the same time, horns and tusks," and "he has never seen a single animal with two horns," Aristotle suggested that Nature, by not giving no animal horns and tusks at the same time, avoided the vanity, and did the creatures that schools that had a necessity. Noting that ruminants have multiple stomachs and weak teeth, he assumes that the first thing was to compensate for the latter, with Nature trying to balance the scales.
Similarly, Aristotle thought that animals could be classified according to a scale of perfection from plants to humans. His system was eleven graduations representing "the degree to which they were affected by the potential", expressed their form at birth. The highest ranked animals put to the world of small hot and humid, unlike those of the bottom gave birth to little cold, dry eggs in the shell thickness. Aristotle also noted that if the shape of a living being reflected its level of perfection, it does not predetermine. He said the quality of the souls of animals was also important. He divided the soul into three groups: plants were equipped with a vegetative soul, which enabled them to reproduce and grow, and animals, a soul both vegetative and sensitive, responsible for mobility and sensation; the man finally had a vegetative soul, sensitive, and rational, capable of thought and reflection. Unlike the older philosophers, Aristotle presented the heart as the seat of the rational soul, rather than the brain and separated the sensations of thought (only Alcmaeon Crotone had previously made this separation).
The successor of Aristotle in the Lyceum, Theophrastus, wrote a series of botanical works, the History of Plants, which was considered the most important contribution during antiquity in botany, and even during the Middle Ages. Many names made by Theophrastus persist even today, as Carpos for fruit and pericarpion for conducting vessels. Instead of focusing on formal causes, as Aristotle did, Theophrastus suggested a mechanistic approach, by creating analogies between natural and artificial processes, and linking the Aristotelian concept of "efficient cause". Theophrastus also recognized the role of sex in the reproduction of many plants evolved, something that was lost in the ages following.