PHILOSOPHY 21:  HISTORY OF EARLY MODERN PHILOSOPHY

FALL 2005

HANDOUT #2

MEDIEVAL PHILOSOPHY AND CULTURE

 

 

 

830                  The Caliph of Baghdad, al-Ma'mun al-Rashid, establishes the "Bayt al-Hikma" (House of Wisdom) to translate the works of Greek antiquity – in effect, the world's first university.

 

980                  Birth of Avicenna (Abu Ali al-Hussein ibn-Sina, 980-1037), Persian philosopher and creator of Arabic Scholasticism.   Influenced by the newly translated works of Aristotle, he rejected the doctrine of the temporal creation of the world by God, but affirmed that the world is eternally dependent upon God for its existence.  Philosophy and religion are 'parallel truths,' with religion a crude philosophy for the uneducated.

 

                        Avicenna distinguished between 'essence' and  'existence'.  As we saw from Aristotle, a species has an 'essence,' the set of necessary properties which distinguishes that species from all others.   However, just by understanding and considering the essence of any species, we cannot determine that any substance which is a member of that species actually exists. (For example, our grasp of the essence of the species Unicorn might be just as firm as our knowledge of  the essence Horse.  But we still have to search the world to discover that: (i) there are horses, (ii) there are no unicorns.)

 

Furthermore, something must cause the individual substances having the essence of a given species to exist.  Our grasp of Horse and Unicorn does not guarantee us any actual, substantial horses or unicorns.  Some other cause must produce the horses themselves, and explain the absence of unicorns.  That cause must be something with another the essences themselves. 

 

We could say that actual horses are produced by other actual horses.   But since there cannot be an infinite regress of such causes – it can’t be horses all the way back, as it were – it becomes clear that there must be an existing essence that does not derive its existence from any other essence. 

 

This necessary existent is God.

 

                        Genuine knowledge results from an intuitive 'act' of illumination, for which reasoning is not a sufficient condition.

 

1126                Birth of Averroes (Abu al-Walid Muhammad ibn Ahmad ibn-Rushd), Spanish-born Arabic philosopher who brought Arabic Scholasticism to its height.  Averroes sought to resurrect the original Aristotelian doctrines by denying Avicenna's essence/existence distinction.

 

                        Averroes’ most influential (and controversial) doctrine was his clarification of Aristotle's obscure notion of the 'active intellect', responsible for the act of knowledge.  Averroes claimed that the human intellect was a separate and unitary substance, possessed in common by all human knowers.  There was only one Active Intellect.  That explains how different knowers can know the same things. But it required that  Averroes deny personal immortality.

 

                        Averroes’ view of the relation between philosophy and theology was a 'double truth' theory:  one and the same truth was expressed clearly and literally in philosophy, but allegorically in theology.

 

1126-51           Avicenna's Logic, Metaphysics, Physics, De Caelo et Mundo (“On the Heavens and the Earth”), are translated from Arabic into Latin by the "School of Toledo,”  a group of Christian scholars who translated the works of Arabic philosophers (as well as Arabic translations of ancient texts). 

 

1134-87           Aristotle's Posterior Analytics, De Caelo et Mundo, De Generatione et Corruptione, De Meterologica, are translated from Arabic into Latin by Gerard of Cremona, a member of the Toledo School.  This marked the introduction of Aristote­lian philosophy and science into the Latin West.  (Aristotle’s logic had never been lost.)

 

1215                Foundation of the University of Paris.  In 1210 the papal authorities forbade universities, under pain of excommunication, to teach the metaphysics and 'natural philosophy' of Aristotle.  The study of Aristotle's logic, on the other hand, was required.  By 1255 all known works of Aristotle have been officially taught at Paris. 

 

1263                The Prohibition of 1210 is renewed by Pope Urban IV out of fear of 'Averroism.' The University of Paris continues to ignore the ban.

 

1273                Thomas Aquinas, Dominican Professor of Theology at Paris, completes his Summa Theologica, a comprehensive synthesis of Aristotelian philosophy with Christian doctrine.  Among its contributions:

-           Uses Aristotelian arguments concerning the first cause and the 'unmoved mover' to provide, in effect, scientific arguments for the existence of God.  (Averroes had done this before.)

 

-           Criticizes the 'Ontological Argument' for existence of God put forward by Anselm in the 11th century.  This argument will be revived by Descartes and other moderns.

-           Uses Avicenna's distinction between 'essence' and 'existence' to devise a concept of God as the being "whose essence it is to exist".  (He also uses a version of Avicenna's argument in his 'Argument from Contingency'.)

 

-           Distinguishes between philosophical truth and theological truth by appeal to the notion of Self-evidence.  For instance, from the nature of God it is self-evident that God exists.  However, it may not be self-evident to human knowers.  Explaining God's nature may be like a mathematical theorem which is true, but which are beyond the capacity of human minds to prove.  Conflicts between established truth in natural philosophy and revealed truth can be reconciled by treating Biblical statements as analogical.

 

-           Like Aristotle, Aquinas thinks that genuine knowledge (including knowledge in natural philosophy) involves the statement of an essence.  That is, knowledge is not of particulars but of 'universals'.  Like Avicenna, Aquinas believed that there is a real distinction between essence and existence – except (of course) in the case of God, whose essence is to exist.

 

-           Agrees with Aristotle that scientific knowledge is demonstrative:  it is deduction of the necessary properties of a particular species of individual from the essence.

 

-           The relation between the essence as it is in objects, and the essence as it is in the mind (the 'passive intellect') is identity.  That is, when we have knowledge we literally know the object -- the essence.

 

-           Criticizes the averroistic doctrine of the unity of the active intellect.  The active intellect is for Aquinas the individual human soul:  the only part of the human being that survives death. 

 

-           Establishes the principle later appealed to by the empiricist philosophers that 'There is nothing in the intellect which is not first in the senses."  (One problem this raises is the mode of knowledge of separated souls before the final resurrection of the body.)

 

1274                Aquinas dies. 

 

1277                The Bishop of Paris condemns certain of Aquinas's theses for averroism.  The University of Paris ignores the condemnation.

 

1305                Johannes Duns Scotus (John Duns the Scot), a Franciscan 'Bachelor of Arts' from Oxford, is appointed a 'Master' (member of the teaching faculty) at the University of Paris.  His lectures are interrupted when he refuses to support King Phillip the Fair in a dispute with Pope Boniface VIII over the right of the King of France to tax Church lands.  This dispute causes a division within the Franciscans and Dominicans at Paris: the French members of those orders generally supporting Phillip, the others (like Scotus, who was from a prominent Border family) supporting Boniface.  Scotus's Ordinatio (requirement for a teaching degree) and Tractatus de Primo Principio (“Treatise on First Principles,” a work in natural theology) produced about this time.   Scotus's doctrines include:

 

-           The most sophisticated version of the Ontological Argument to date -- perhaps the most sophisticated ever.

 

-           The true cause of any effect cannot precede the effect, but must coexist with the effect and conserve it.  Anticipates Hume's criticism of 'causal chain' explanations.

 

-           Develops a compromise (against realists like Aquinas and 'nominalists' like Ockham) between asserting a real distinction between essence and existence in things and asserting that the distinction is merely 'nominal' or 'conceptual.’  Scotus's 'formal distinction’ explains how universal scientific knowledge, based as it is upon experience with individuals, can be valid.

 

-           The notion of 'haecceity' -- individual essence.  Scotus used ‘haecceities’to explain how two or more substances of the same species can nevertheless be non-identical individuals.

 

1323                Aquinas is canonized.  The current Bishop of Paris revokes Tempier's condemnation.

 

1328                                                    William of Ockham, Franciscan logician, produces first part of Summa Logicae and the Tractatus Noventa Dierum.  Born between 1280 and 1290, Ockham receives his BA about 1323, but never becomes a 'Master'.  In 1324 Ockham called to Avignon, then the Papal residence to defend himself against accusations of teaching 'dangerous doctrines'.  During that time he becomes involved in the dispute between the Franciscans and Pope John XXII on whether Christ and the Apostles owned private property.

 

                                                            In 1328 Ockham, together with the General of the Franciscan Order, Michael of Cesena, escape from Avignon and flee to Munich under the protection of the Emperor, Louis of Bavaria.   Some of his philosophical doctrines include:

 

                                                -           The distinction between essence and existence is 'conceptual'.  In short, only individuals exist.

 

                                                -           Whatever God produces by means of secondary causes He can produce immediately and without their aid.  Furthermore, God can produce every reality apart from any other reality.

 

                                                            That is, scientific laws will be summaries of what actually does happen, but not law-like explanations of why events must happen the way they do.