Theophrastus in the context of "Folk taxonomy"

The history of biology traces the study of the living world from ancient to modern times. Although the concept of biology as a single coherent field arose in the 19th century, the biological sciences emerged from traditions of medicine and natural history reaching back to Ayurveda, ancient Egyptian medicine and the works of Aristotle, Theophrastus and Galen in the ancient Greco-Roman world. This ancient work was further developed in the Middle Ages by Muslim physicians and scholars such as Avicenna. During the European Renaissance and early modern period, biological thought was revolutionized in Europe by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were Vesalius and Harvey, who used experimentation and careful observation in physiology, and naturalists such as Linnaeus and Buffon who began to classify the diversity of life and the fossil record, as well as the development and behavior of organisms. Antonie van Leeuwenhoek revealed by means of microscopy the previously unknown world of microorganisms, laying the groundwork for cell theory. The growing importance of natural theology, partly a response to the rise of mechanical philosophy, encouraged the growth of natural history (although it entrenched the argument from design).

Over the 18th and 19th centuries, biological sciences such as botany and zoology became increasingly professional scientific disciplines. Lavoisier and other physical scientists began to connect the animate and inanimate worlds through physics and chemistry. Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, and the ways this relationship depends on geography—laying the foundations for biogeography, ecology and ethology. Naturalists began to reject essentialism and consider the importance of extinction and the mutability of species. Cell theory provided a new perspective on the fundamental basis of life. These developments, as well as the results from embryology and paleontology, were synthesized in Charles Darwin's theory of evolution by natural selection. The end of the 19th century saw the fall of spontaneous generation and the rise of the germ theory of disease, though the mechanism of inheritance remained a mystery.

In propositional logic, modus tollens (/ˈmoʊdəs ˈtɒlɛnz/) (MT), also known as modus tollendo tollens (Latin for "mode that by denying denies") and denying the consequent, is a deductive argument form and a rule of inference. Modus tollens is a mixed hypothetical syllogism that takes the form of "If P, then Q. Not Q. Therefore, not P." It is an application of the general truth that if a statement is true, then so is its contrapositive. The form shows that inference from P implies Q to the negation of Q implies the negation of P is a valid argument.

The history of the inference rule modus tollens goes back to antiquity. The first to explicitly describe the argument form modus tollens was Theophrastus.

Demetrius of Phalerum (also Demetrius of Phaleron or Demetrius Phalereus; Ancient Greek: Δημήτριος ὁ Φαληρεύς; c. 350 – c. 280 BC) was an Athenian orator originally from Phalerum, an ancient port of Athens. A student of Theophrastus, and perhaps of Aristotle, he was one of the first members of the Peripatetic school of philosophy. Demetrius had been a distinguished statesman who was appointed by Cassander, the King of Macedon, to govern Athens, where Demetrius ruled as sole ruler for ten years. During this time, he introduced important reforms of the legal system, while also maintaining pro-Cassander oligarchic rule.

Demetrius was exiled by his enemies in 307 BC. He first went to Thebes, and then, after 297 BC, went to the court of Alexandria. He wrote extensively on the subjects of history, rhetoric, and literary criticism. He is not to be confused with his grandson, also called Demetrius of Phaleron, who probably served as regent of Athens between 262 and 255, on behalf of the Macedonian King Antigonos Gonatas.

Adrantus (Ancient Greek: Ἄδραντος), or Ardrantus or Adrastus, was a contemporary of Athenaeus in the 2nd or 3rd century AD who wrote a commentary in five books upon the work of Theophrastus, entitled Περὶ Ἠθῶν, to which he added a sixth book upon the Nicomachean Ethics of Aristotle.

Nicomachus (Greek: Νικόμαχος; fl. c. 325 BC) was the son of Aristotle. The Suda states that Nicomachus was from Stageira, was a philosopher, a pupil of Theophrastus, and, according to Aristippus, his lover. He may have written a commentary on his father's lectures in physics. Nicomachus was born to the slave Herpyllis, and his father's will commended his care as a boy to several tutors, then to his adopted son, Nicanor. Historians think the Nicomachean Ethics, a compilation of Aristotle's lecture notes, was probably named after or dedicated to Aristotle's son. However, Nicomachus is also believed to be the name of Aristotle's father. Several ancient authorities may have conflated Aristotle's ethical works with the commentaries that Nicomachus wrote on them. Ancient sources indicate that Nicomachus died in battle while still a "lad".

Hermippus of Smyrna (Greek: Ἕρμιππος ὁ Σμυρναῖος) was a Greek grammarian and peripatetic philosopher, surnamed by the ancient writers the Callimachian (Greek: ό Καλλιμάχειος), from which it may be inferred that he was a disciple of Callimachus about the middle of the 3rd century BC, while the fact of his having written about the life of Chrysippus proves that he lived to about the end of the century. His writings seem to have been of very great importance and value. They are repeatedly referred to by the ancient writers, under many titles, of which, however, most, if not all, seem to have been chapters of his great biographical work, which is often quoted under the title of Lives (Bioi). The work contained the biographies of a great many ancient figures, including orators, poets, historians, and philosophers. It contained the earliest known biography of Aristotle, as well as philosophers such as Pythagoras, Empedocles, Heraclitus, Democritus, Zeno, Socrates, Plato, Antisthenes, Diogenes, Stilpo, Epicurus, Theophrastus, Heraclides, Demetrius Phalereus, and Chrysippus. The work has been lost, but many later Lives extensively quote it.

Josephus and Origen cite Hermippus to argue that Pythagoras owed a debt to Judaism.

In classical logic, a hypothetical syllogism is a valid argument form, a deductive syllogism with a conditional statement for one or both of its premises. Ancient references point to the works of Theophrastus and Eudemus for the first investigation of this kind of syllogisms.

Phaenias of Eresus (Ancient Greek: Φαινίας ὁ Ἐρέσιος, Phainias; also Phanias (Φανίας)) was a Greek philosopher from Lesbos, important as an immediate follower of and commentator on Aristotle. He came to Athens about 332 BCE, and joined his compatriot, Theophrastus, in the Peripatetic school. His writings on logic and science appear to have been commentaries or supplements to the works of Aristotle and Theophrastus. He also wrote extensively on history. His works have only survived in fragments quoted by other authors.

Sotion of Alexandria (Ancient Greek: Σωτίων, gen.: Σωτίωνος; fl. c. 200 – 170 BC) was a Greek doxographer and biographer, and an important source for Diogenes Laërtius. None of his works survive; they are known only indirectly. His principal work, the Διαδοχή or Διαδοχαί (the Successions), was one of the first history books to have organized philosophers into schools of successive influence: e.g., the so-called Ionian School of Thales, Anaximander and Anaximenes. It is quoted very frequently by Diogenes Laërtius, and Athenaeus. Sotion's Successions likely consisted of 23 books, and at least partly drew on the doxography of Theophrastus. The Successions was influential enough to be abridged by Heraclides Lembus in the mid-2nd century BC, and works by the same title were subsequently written by Sosicrates of Rhodes and Antisthenes of Rhodes.

He was also, apparently, the author of a work, On Timon's Silloi, and of a work entitled Refutations of Diocles.