Aristotelianism, Renaissance

« of Medicine, Galen distinguishes between what he calls the method of resolution, in which an object is broken downinto its component parts, and the method of composition, in which the components used in the resolution are putinto their proper order.

Late medieval Aristotelians, like Pietro d'Abano (1257-1315) in his Conciliator differentiarumphilosophorum et praecipue medicorum (Conciliator of the Differences between Philosophers and EspeciallyPhysicians) (composed around 1300), conflated demonstration quia and propter quid with resolution andcomposition, and were thus able to offer a sophisticated account of both the method of scientific discovery and theproper way to order such knowledge.

Paul of Venice , a member of the Augustinian Order who studied at Oxford before returning to teach at Padua, sets forth the procedure of going from effect to cause and back to the effect,and defends it against the charge of circularity.

He is also careful to note that demonstration in natural sciencedoes not yield the necessity and certitude of mathematics, since it deals with what happens for the most part.Natural science is thus a demonstrative science, but is only a science of what usually occurs.

Two contemporariesof Paul, Hugo of Siena and Jacopo da Forli, also discuss the resolutive method.

However, it is Nicoletto Vernia (§3) who examines in greater depth questions regarding demonstration and the resolutive method in his Paduan lectureson the Posterior Analytics.

Vernia also takes up the question whether demonstration is circular.

He points out thatthere must first be a movement from an effect by way of demonstration quia but thereafter there must be a returnback to the effect if natural science is to be perfect.

That is to say, after the resolution ( resolutio) of an 'effect' -that is, what is experienced through the senses - into an initial universal knowledge, we still lack demonstrationpropter quid, which is knowledge based on the essential principles of the thing.

Vernia therefore postulates amovement of the intellect (negotiatio intellectus) enabling it somehow to discern the true cause of the effect andthe necessary causal connection of that cause to its effect.

A genuine apodictic demonstration propter quid is theresult.

The topic of resolutive or regressive method (regressus) was also treated by Agostino Nifo (§2) , Vernia's former student.

In his youth he too postulated a movement of the intellect (negotiatio intellectus) enabling it todiscern the true cause of an effect so that a strict demonstration was possible.

However, later in his career, afterstudying the Greek commentators, namely Alexander of Aphrodisias , Themistius , Simplicius and Philoponus , he denied the need for such a special movement of the intellect and held that the most that could be achieved in naturalscience Routledge Encyclopedia of Philosophy, Version 1.0, London and New York: Routledge (1998) Aristotelianism,Renaissance was a hypothetical syllogism and a hypothetical demonstration.

Discussions regarding thesemethodological issues are also to be found in such contemporaries as Marcantonio Zimara and BernardinusTomitanus (d.

1576).

But it is Jacopo Zabarella (§5) , a student of Tomitanus, who stands at the end of this long line of development.

In his treatise De regressu (On the Regress), Zabarella sets forth a systematic discussion ofthe nature of scientific investigation in which he assumes like the earlier theorists a basic continuity betweenAristotle and Galen.

He argues that demonstration quia provides us with a method of reasoning from effect tocause, but does not tell us the proper reason for the effect.

Nevertheless, from the cause to which our initialknowledge of the effect leads, we can eventually achieve a full account of the proximate cause of the effect.

Thatis, we can arrive at an argument that fully reveals the cause by giving a propter quid demonstration that states thereason why.

What keeps this regressive method from being purely formal is the positing of the intermediate step ofthe movement (negotiatio) of the intellect, going from an initially confused and improper knowledge of the cause toa distinct and proper knowledge of it (see Galilei, Galileo ).

3 Natural philosophy One of the issues discussed by medieval Aristotelians that continued to concern Aristotelian philosophers during the Renaissance was theidentification of the subject of natural philosophy.

This issue was thought to be important because it concerned notonly the relationship between metaphysics (the science of being qua being) and natural philosophy, but also theplace of immaterial created beings, such as angels, within Aristotelian science.

Thomas Aquinas (§9) had argued that mobile or changeable being (ens mobile), which seems to include all beings liable to change (that is, everythingother than God), was the subject of natural philosophy, whereas his teacher Albert the Great (§4) took it to be mobile or changeable body (corpus mobile).

Later, Paul of Venice states that the subject matter is natural body (corpus naturale), while his student, Cajetan of Thiene (Gaetano da Thiene) (1387-1485), maintained that it issensible substance (substantia sensibilis).

Subsequently the whole issue was approached in a systematic fashion byCajetan's student, Nicoletto Vernia (§3) , who composed a separate question on whether mobile being is the subject of all natural philosophy.

In it he reviews and compares a wide range of authors including Antonius Andreas and JohnCanonicus, whom he attacks for judging Aristotle to have erred in natural philosophy.

Vernia accuses them of notspeaking naturally but rather introducing theological considerations into the discussion, namely the question of themotion of angels.

Vernia himself upholds and defends mobile being as the subject, which he took to be the positionof Averroes.

Thereafter Vernia's student Agostino Nifo (§2) took up the question of the subject matter of natural philosophy in his commentary on the Physics.

He rejects the respective positions of Albert and Aquinas but thenattempts to conciliate them, arguing that mobile being can be considered the subject of natural science if bysubject is meant the genus or most general predicate applying to the things considered in natural science, whereasmobile body can also be considered the subject if by that is meant the most general species to which all and onlythe things considered in natural science belong.

He presents Averroes as holding that the total subject of naturalscience is a sensible thing (res sensibilis) in so far as it moves, that is, in so far as it contains the principle ofmotion.

Jacopo Zabarella (§6) who, like Vernia, wrote a systematic work on the question of the subject of natural philosophy, echoes the earlier discussions.

He declares the common subject of all natural science to be body takenuniversally (embracing both the earthly bodies and also the bodies in the heavens), but in so far as body has withinit a nature (that is, the principle of motion).

He insists that this is the position of Aristotle (§10) in the Physics and On the Heavens.

As to the subject of Aristotle's On the Soul, he takes it to be animate body (corpus animatum).Further echoes of the discussion are still found in the seventeenth century (see John of St Thomas §3 ).

Another issue in the area of natural philosophy that merits mention is the challenge of Richard Swineshead and thefourteenth-century Oxford Calculators' tradition of interest in physics (see Oxford Calculators ).

Central was their doctrine of measuring the intension and remission of forms, that is, physical properties, and stating thismeasurement in mathematical language.

Paul of Venice was one of those who brought this manner of doing natural. »