The Problem of Causal Inference in the Empirical World of Nicholas of Autrecourt

This is not to say that Nicholas was unaware of some of the work going on in such areas as optics, mathematics, and other sciences.

Exigit ordo executionis, ed. by O'Donnell J. R. in his “Nicholas of Autrecourt”, Medieval studies, i (1939), 179–280, quotation from p. 184.

“Itaque proposui inter cetera contra sic deceptos aliquas conclusiones quas certum fuisse de intellectu Aristotelis et quas in dubium non revocant ostendere ab eis nullo modo fore scitas. In cuiusmodi processu erant quam plurimae conclusiones super (quibus) non determinando sed dubitando inquiretur”, ibid., 198. For a detailed account of Nicholas's thought, see Weinberg J. , Nicholaus of Autrecourt (Princeton, 1948). See also Moody E. A. , “Ockham, Buridan and Nicholas of Autrecourt”, Franciscan studies, vii (1947), 113–46; Lappe J. , Nicholaus von Autrecourt, sein Leben, seine Philosophie, seine Schriften , in Beiträge zur Geschichte der Philosophie des Mittelalters, vi/2 (1908), espec. pp. 1–8. For more recent evaluations of Nicholas's work, see Crombie A. C. , Augustine to Galileo, ii (London, 1952; rev. edn, London, 1959); Leff Gordon , Medieval thought (London, 1959); Dijksterhuis E. J. , The mechanization of the world picture, transl. by Dikshoorn C. (Oxford, 1961); Courtenay William , “Covenant and causality in Pierre d'Ailly”, Speculum, January 1971, 94–119. The basic texts of Nicholas of Autrecourt are: Exigit ordo executionis, ed. by O'Donnell , and Epistolae ad Bernardum ab Arezzo, quoted in Articles of Cardinal Curty in O'Donnell's edn. Unless otherwise stated, translations are by Kennedy L. A. Arnold R. and Millward A. E. , from The universal treatise of Nicholas of Autrecourt (Milwaukee, 1971). See also Courtenay William J. , “John of Mirecourt and Gregory of Rimini on whether God can undo the past”, RTAM, xxxix (1972), 224–56; xl (1973), 147–74; and Murdoch John , “The development of a critical temper: New approaches and modes of analysis on fourteenth-century philosophy, science and theology”, in Medieval and Renaissance studies, ed. by Wenzel Siegfried (Chapel Hill, 1978), 51–79.

“Ex hac siquidem conclusione possunt concludi de dictis Aristotelis in diversis locis esse falsa, et interdum in quibusdam est solum fictio”, Exigit, 204.

“Item mirabile est qualiter reputant illa esse principia per se nota in quorum oppositis quasi concordaverunt omnes qui Aristotelem praecesserunt, saltem sollemniores …. Amplius philosophantes non admittant eos in talibus verbositatibus quibus clipeisant [sic] illi, qui nesciunt resistere veritati”, Exigit, 203.

“Omnis certitudo a nobis habita resolvitur in istud principium, et ipsum non resolvitur in aliquod aliud sicut conclusio in principium suum. Igitur sequitur, quod ipsum est primum …”, Lappe, op. cit. (ref. 3), 7.

“… quia est certitudo habita virtute primi principii, cui lex nulla vera contradicit nec contradicere potest. Et ideo, quod est demonstratum in lumine naturali, est demonstratum simpliciter: Nec per aliquam potentiam posset fieri quod oppositum consequents staret simul cum antecedente, sicut nec aliqua potentia potest facere, quod contradictoria sint simul vera”, ibid., 7.

“… ut si sint due conclusiones, de quarum qualibet sumus certi evidenter, non sumus magis certi de una quam de alia. Nam, ut dictum est, omnis certitudo reducitur in idem primum principium”, ibid., 8.

“… potest nobis faciliter apparere quid intelligatur per certitudinem; hoc enim nomine per certam cognitionem respectu alicujus complexi, eius enim quid nominis, utuntur homines sic: Cum aliquis habet cognitionem claram et evidentem complexi quod sic habeat et etiam percipit se habere talem cognitionem claram et evidentem, tunc dicit quod est certus”, Exigit, 235.

Gilson, commenting on Aquinas's formulation of these divisions, writes, “… the unity of [Aquinas's] theology is that of an organic whole whose parts are united …, [it] includes what God has revealed, … what the theologian deduces … [and] includes all the material provided by logic, the sciences of nature and metaphysics …”, Gilson Etienne , History of Christian philosophy in the Middle Ages (New York, 1955), 367.

“Ex eo, quod aliqua res est cognita esse, non potest evidenter reducta in primum principium vel in certitudinem primi principii inferri, quod alia res sit”, Lappe , op. cit. (ref. 3), 115–20. Four centuries later, David Hume wrote: “[The sceptic] seems to have ample matter of triumph, while he justly insists that all our evidence for any matter of fact which lies beyond the testimony of sense or memory is derived entirely from the relation of cause and effect; that we have no other idea of this relation than that of two objects which have been frequently conjoined together … and that nothing leads us to this inference but custom or a certain instinct in our nature which it is indeed difficult to resist, but which … may be fallacious and deceitful”, Enquiry concerning human understanding , in The philosophical works of David Hume , ed. by Green T. H. and Grose T. H. (London, 1875), 159. E. A. Moody comments: “In abandoning substances, he [Nicholas] quite logically dispenses with causality, he dispensed with causal explanations, and consequently all the natural sciences which demonstrate through causes. He was left, like Hume, with only two types of cognition: The tautological certainties of the principles of identity and contradiction, and the subsequent certainty of awareness of his own acts of thinking, and of perception of the qualities apprehended by his five senses”, Moody E. A. , Studies in Medieval philosophy, science, and logic (Berkeley, 1975), 154.

“Et intellige quod omnis causa aeque faciliter producit suum effectum quantum est de se, quia omnis causa uniformiter comparatur suo effectui”, Exigit, 258. Peter King comments: “… William of Ockham maintained that knowledge of the effect was never sufficient for knowledge of the cause, and Nicholas of Autrecourt gave an analysis of causation which drove him to deny all knowledge not strictly entailed by the Law of Noncontradiction or confined to immediate experience”, “Jean Buridan's philosophy of science”, Studies in history and philosophy of science, xviii (1987), 109–32.

“… sed interdum aliquae causae impediuntur et aliae succedunt. … Unde pone virtutem calefactivam perfectissimam quae copulatur cum igne perfectissimo approximato aquae frigidissimae quam consequitur virtus frigefactiva perfectissima; non intelligo quod calor remissus producatur ab illa virtute perfectissima quia illa non potest agere nisi secundum modum suae naturae; sed istae virtutes se impediunt; sic tamen consequuntur quaedam aliae virtutes quae non sunt sic perfectae quae inducunt suos effectus”, Exigit, 258.

“Nunc quando dicitur illud suppositum corrumpi non est nisi segregatio corporum atomalium”, ibid., 189.

“Considerandum quia supradixi quod quando res dicitur corrumpi non est aliud nisi segregatio corporum quae dispergunt se et dividunt se …”, ibid., 188.

“Sic hic habeo media satis probabilia ad concludendum quod conclusio de aeternitate rerum est probabilis …”, ibid., 189.

“… sed ex quibus probetus diversitas rationum inferius forsitans apparebit”, ibid., 205.

Atomism was occasionally mentioned in the Middle Ages, but nowhere were its possible implications explored. See Crombie A. C. , Augustine to Galileo (ref. 3), rev. edn, ii, 51ff.

“Sed quaeret aliquis: Ex quo substantia materialis et quantitas non distinguuntur, numquid ista sit concedenda: Substantia materialis est quantitas? Dico quod ista possunt accipi dupliciter; vel praecise ut signa rerum extra animam, et ut sic concederem propositionem esse veram … et isti sunt diversi conceptus”, Exigit, 226.

“Sic ergo in rebus naturae non est nisi motus localis; sed quando ad talem motum sequitur congregatio corporum naturalium quae colliguntur ad invicem et sortiuntur naturam unius suppositi dicitur generatio; quando segregantur, dicitur corruptio, et quando per motum localem corpora atomalia <conjunguntur> cum aliquo supposito quae sunt talia, quod nec adventus ipsorum fieri videtur ad motum suppositi, nec ad illud quod dicitur operatio naturalis ejus, tunc dicitur alteratio. Et forsan sicut adamas ferrum, ita est ibi unum quod connectit et retinet in tali colligatione ipsa indivisibilia …”, ibid., 200–1.

“… apparet quod vos habetis dicere, quod vos non estis certus de illis, que sunt extra vos. Et ita nescitis, si sitis in celo vel in terra, in igne vel in aqua, et per consequens nescitis, si hodie sit idem celum, quod heri fuit, quoniam nec scitis, si celum fuit, vel sicut etiam nescitis. Si Cancellarius vel Papa sit, et si isti sint, an sint alii et alii homines in quolibet momento temporis. Similiter nescitis, que sunt infra vos, ut si habetis barbam, capillos etcetera. Ex isto sequitur a multo fortiori, quod vos non estis certus de his, que transierunt in preteritum, ut si legistis, vidistis vel audistis. Item dicta vestra videntur ad destructionem civilitatis et politie, quia, si testes deponant de visis, non sequitur: Vidimus, ergo ita fuit”, Lappe , op. cit. (ref. 3), 5.

“… sed de qualitatibus sensibilibus quae nunc sunt est intellectus vel esse potest, certus quod sunt”, Exigit, 198.

“Oportet ergo quod sit nota per experientiam ex actibus sensuum quos experimur in nobis …. Et hoc apparet ex alio quia illud videtur mediare apud intellectum respectu alicujus complexi ad quod quasi naturaliter recurritur cum quaeritur de complexo. Sed cum quaeritur: Est ista aqua calida?, statim recurrunt homines ad actum tactus; cum quaeritur: Estne hic paries albus?, recurritur ad actum visus et sic in aliis”, ibid., 199.

“… quod de scitis per experientiam illo modo quo dicitur sciri rheubarbarum sanat choleram vel adamas attravit ferrum …”, ibid., 237.

“Probabile igitur est quod omne illud quod apparet est verum, scilicet quod est clarum et evidens in pleno lumine; alias enim non esset certus de quoquam intellectus quoniam de nullo intellectus potest se dicere esse certum nisi illud experiatur in se vel ex experientiis suis concludatur sicut sunt illa quae ad experientias suas consecutione naturali consequuntur”, ibid., 230.

“… propter quod frivole arguunt dicentes: Apparet dormiendo me currere per castra vel esse in caelo et tamen ita non est. Respondeo: Non apparebat tibi apparentia plena; nam apparentia plena veritatis huius propositionis est apparentia sensuum exteriorum quando per visum vides motum …”, ibid., 231.

“Et forsan finaliter oporteret quod non habemus plenam certitudinem de rebus, immo solum eam habet intellectus primus qui est mensura omnium intellectuum”, ibid., 232.

“Nunc in speculativis non quaerimus nisi ipsum scire ut res veniat in apparentia apud animam. Non est sicut in observantiis legalibus ubi quaeritur non cognitio sed opus; et ideo ibi talibus argumentis utitur legislator ut homines inducat ad assensum; nam scit quod assensu posito sequetur opus. Sed hic non quaerimus nisi evidentiam, et ideo non videtur quod dignum sit uti talibus argumentis; sed quaeramus veritatem quaesitorum in propositionibus per se notis in experimentis”, ibid., 184.

“… videretur enim aliquibus forsan non magnum bonum esse habere notitiam rerum eo quod dictum est de ipsis non habere nos plenam certitudinem. Et responsio in hoc esset quod esto quod sic sit, non multum obstat; nam certum est quod sunt aliquae configurationes et aliqua lumina cujuscumque objecti sint; non multum refert nisi quod secundum hoc remaneret desiderium non terminatum super notitia rerum”, ibid., 234.

In the prologue of the Exigit, Nicholas explains his motive for writing it. He tells how wrong he thinks it that scholars spend twenty or thirty years studying Aristotle and deserting moral matters and concern for the common good, in their fruitless, endless preoccupation with ‘a thousand conclusions’ which were, in his opinion, either incorrect or of little worth.

Leff Gordon , “The changing pattern of thought in the earlier fourteenth century”, Bulletin of the John Rylands Library, xliii, no. 2 (March 1961), 354–72, p. 370.

“Consideravi … quarto qualiter omnes propter logicos sermones Aristotelis … deserebant res morales et curam boni communis …”, Exigit, 181.

“… vidi quod de rebus per apparentia naturalia quasi nulla certitudo potest metiri et quod brevi tempore illud, quod potest haberi, habebitur si homines sic immediate intellectum suum convertant ad res sicut fecerunt ad intellectum hominum Aristotelis et commentatoris Averrois. Cum etiam apparuit quod homines modicum debent adhaerere apparentibus naturalibus, apud me hoc venit judicium quod, si hoc cognoscerent bene nati communitatis politicae, converterent se ad res moris et adhaererent firmiter legi sacrae, legi christianae quae inter omnes honestissimum modum vivendi complexa est viverent in caritate …”, ibid., 181. Denys Hay writes: “… many thinkers were then groping towards a position which would release speculation from the ordered legalism of the thirteenth century scholastics, which would admit the perception of ‘individuals’ rather than accept only an awareness of abstract form or essence wrapped up in ‘accidents’ of texture, color, shape and the like. Many men were feeling their way towards a direct intuitive knowledge of the physical world”, Europe in the fourteenth and fifteenth centuries (New York, 1966), 340.

Dijksterhuis , op. cit. (ref. 3), 170.

In the first quarter of the fourteenth century — just around the time that Nicholas was studying at the Sorbonne — the sceptical thought of the Arab thinker al-Gazali (d. 1111) was translated and interpreted by Averroës (d. 1178) in his Destructio destructionis. It is possible that Nicholas read this work; and it is very likely that he was also acquainted with the Pyrrhonic hypotyposes of Sextus Empiricus, which was made available in the thirteenth century.

“Et si istae rationes non reperirentur omnino concludere, tamen probabiliis est positio et probabilior rationibus conclusionis oppositae …. Sic loquor quia in libris aliorum ad conclusiones occultas paucas vidi rationes ad quas nescirem probabiles dare responsiones …”, Exigit, 203.

See Articles of Cardinal Curty in Lappe , op. cit. (ref. 3), 31–35.

For a discussion of this topic, see Leff Gordon , William of Ockham: The metamorphosis of scholastic discourse (Manchester, 1975).