Philo the Dialectician ( el, Φίλων;
fl.
''Floruit'' (; abbreviated fl. or occasionally flor.; from Latin for "they flourished") denotes a date or period during which a person was known to have been alive or active. In English, the unabbreviated word may also be used as a noun indicatin ...
300 BC) was a
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
philosopher of the
Megarian (Dialectical) school. He is sometimes called Philo of Megara although the city of his birth is unknown. He is most famous for the debate he had with his teacher
Diodorus Cronus
Diodorus Cronus ( el, Διόδωρος Κρόνος; died c. 284 BC) was a Greek philosopher and dialectician connected to the Megarian school. He was most notable for logic innovations, including his master argument formulated in response to A ...
concerning the idea of the
possible and the criteria of the truth of
conditional statements.
Life
Little is known about the life of Philo. He was a disciple of
Diodorus Cronus
Diodorus Cronus ( el, Διόδωρος Κρόνος; died c. 284 BC) was a Greek philosopher and dialectician connected to the Megarian school. He was most notable for logic innovations, including his master argument formulated in response to A ...
, and was a friend of
Zeno
Zeno ( grc, Ζήνων) may refer to:
People
* Zeno (name), including a list of people and characters with the name
Philosophers
* Zeno of Elea (), philosopher, follower of Parmenides, known for his paradoxes
* Zeno of Citium (333 – 264 BC), ...
, the founder of
Stoicism
Stoicism is a school of Hellenistic philosophy founded by Zeno of Citium in Athens in the early 3rd century BCE. It is a philosophy of personal virtue ethics informed by its system of logic and its views on the natural world, asserting tha ...
.
Diogenes Laërtius
Diogenes Laërtius ( ; grc-gre, Διογένης Λαέρτιος, ; ) was a biographer of the Greek philosophers. Nothing is definitively known about his life, but his surviving ''Lives and Opinions of Eminent Philosophers'' is a principal sour ...
states that Zeno "used to dispute very carefully with Philo the logician and study along with him—hence Zeno, who was the junior, had as great an admiration for Philo as his master Diodorus."
Jerome
Jerome (; la, Eusebius Sophronius Hieronymus; grc-gre, Εὐσέβιος Σωφρόνιος Ἱερώνυμος; – 30 September 420), also known as Jerome of Stridon, was a Christian priest, confessor, theologian, and historian; he is co ...
refers to Philo as the teacher of
Carneades
Carneades (; el, Καρνεάδης, ''Karneadēs'', "of Carnea"; 214/3–129/8 BC) was a Greek philosopher and perhaps the most prominent head of the Skeptical Academy in ancient Greece. He was born in Cyrene. By the year 159 BC, he had be ...
, which is chronologically impossible. Diogenes Laërtius mentions a (presumably different) Philo who was a disciple of
Pyrrho
Pyrrho of Elis (; grc, Πύρρων ὁ Ἠλεῖος, Pyrrhо̄n ho Ēleios; ), born in Elis, Greece, was a Greek philosopher of Classical antiquity, credited as being the first Greek skeptic philosopher and founder of Pyrrhonism.
Life
...
.
Writings
One of Philo's works was called ''Menexenus'' in which he mentioned the five daughters of Diodorus who were all distinguished dialecticians. Two of
Chrysippus
Chrysippus of Soli (; grc-gre, Χρύσιππος ὁ Σολεύς, ; ) was a Greek Stoic philosopher. He was a native of Soli, Cilicia, but moved to Athens as a young man, where he became a pupil of the Stoic philosopher Cleanthes. When C ...
' logical works were responses to books by Philo, one was directed at "Philo's Work on Meanings", and the other at "Philo's Work on Moods".
Philosophy
Philo disputed with Diodorus respecting the idea of the
possible and the criteria of the truth of
conditional statements.
In regards to things possible, Diodorus maintained that possible was identical with necessary, i.e. that possible is "that which either is or will be true".
Philo instead defined possible as "that which is capable of being true by the proposition's own nature",
thus a statement like "this piece of wood can burn" is possible, even if it spent its entire existence on the bottom of the ocean.
Both Philo and Diodorus sought for criteria for the correct form of conditional propositions, and each of them did so in a manner corresponding to what he maintained respecting the idea of the possible. Philo regarded a conditional as true unless it has both a true
antecedent and a false
consequent
A consequent is the second half of a hypothetical proposition. In the standard form of such a proposition, it is the part that follows "then". In an implication, if ''P'' implies ''Q'', then ''P'' is called the antecedent and ''Q'' is called ...
. Precisely, let ''T
0'' and ''T
1'' be true statements, and let ''F
0'' and ''F
1'' be false statements; then, according to Philo, each of the following conditionals is a true statement, because it is not the case that the consequent is false while the antecedent is true (it is not the case that a false statement is asserted to follow from a true statement):
* If ''T
0'', then ''T
1''
* If ''F
0'', then ''T
0''
* If ''F
0'', then ''F
1''
The following conditional does not meet this requirement, and is therefore a false statement according to Philo:
* If ''T
0, then ''F
0''
Indeed, Sextus says "According to [Philo], there are three ways in which a conditional may be true, and one in which it may be false."
[Sextus Empiricus, ''Adv. Math.'' viii, Section 113] Philo's criterion of truth is what would now be called a
truth-functional definition of "if ... then"; it is the definition used in
modern logic.
In contrast, Diodorus allowed the validity of conditionals only when the antecedent clause could never lead to an untrue conclusion.
[Cicero, ''Academica'', ii. 47, ''de Fato'', 6.] A century later, the
Stoic
Stoic may refer to:
* An adherent of Stoicism; one whose moral quality is associated with that school of philosophy
* STOIC, a programming language
* ''Stoic'' (film), a 2009 film by Uwe Boll
* ''Stoic'' (mixtape), a 2012 mixtape by rapper T-Pain
* ...
philosopher
Chrysippus
Chrysippus of Soli (; grc-gre, Χρύσιππος ὁ Σολεύς, ; ) was a Greek Stoic philosopher. He was a native of Soli, Cilicia, but moved to Athens as a young man, where he became a pupil of the Stoic philosopher Cleanthes. When C ...
attacked the assumptions of both Philo and Diodorus.
References
External links
*
Selected Bibliography on the "Master Argument" in Diodorus Cronus and Philo the Dialecticianwith a bibliography on the problem of future contingents
{{DEFAULTSORT:Philo The Dialectician
Hellenistic-era philosophers
4th-century BC philosophers
Megarian philosophers
Ancient Greek logicians