5. DIFFICULTIES
17
the functioning of the sensitive soul applies equally to humans and the brute
animals, who by definition lack intellective souls. Second, the intellective
soul is immaterial (held on the grounds of faith if nothing else); that means
it is not the form of any given sense-organ, or, to put the same point another
way, the intellect has no means whereby to pick up information about the
world. Hence any material processed by the intellect must already be in the
soul, and the only way for it to get there is through the senses.
Next, Buridan argues that sensitive cognition is always singular.
26
How-
ever, he rejects the traditional claim that the singularity of sensitive cog-
nition follows from the fact that the sensitive soul, unlike the intellective
soul, is material and extended:
27
He offers two reasons. First, the sensitive
appetite is just as material and extended as sensitive cognition, yet sen-
sitive appetite is not targeted at individuals. A thirsty horse wants some
water, but no particular water more than any other. This holds generally:
natural agents acting as causes seem not to single out individuals qua indi-
viduals. Fire heats up any wood in the range of its causal activity; it is not
restricted to acting only on some particular piece of wood. The inference
from materiality to singularity fails in these cases; why think it holds in
sensitive cognition?
28
Second, our perceptual abilities do not seem to put
us in touch with individuals. After all, Buridan notes, we cannot tell the
26
See the end of QSP 1.07 fol. 8va cited in the preceding note. Buridan thinks that
Aristotle endorses this claim in De anima 3.07 431
b
1–20, which he summarizes in
QDA(1) 1.04 196.82–83 as follows: “Sicut patet tertio huius: dicitur enim ibi quod
sensus est singularium.”
27
QDA (3) 3.08 167–170: “Visum fuit aliquibus quod sensus, ex eo quod habet exten-
sionem et situm determinatum in organo corporeo, non habet naturam cognoscendi
uniuersaliter sed singulariter.” See also QSP 1.07 fol. 8va. (Buridan also rejects the
parallel inference from the intellect’s immateriality to its universal cognition.
28
QSP 1.07 fol. 8va–b: “Tertio quia appetitus sensitiuus ita est extensus et materialis
sicut sensus, et tamen equus et canis per famem et sitim appetunt modo uniuersali,
non enim hanc aquam uel auenam magis quam illam sed quamlibet indifferenter; ideo
quodcumque eis portetur, bibunt ipsum uel comedunt. Et est intentio posita uel ap-
petitus ignis ad calefaciendum est modo uniuersali, non determinate ad hoc lignum
sed ad quodlibet calefactibile indifferenter, licet actus calefaciendi determinetur ad
certum singulare. Et ita potentia uisiua est modo uniuersali ad uidendum.” Cfr.
QDA (3) 3.08 223–232: “Et iterum apparet quia uirtus materialis et extensa fertur
bene in obiectum suum modo uniuersali, nam appetitus equi secundum famem aut
situm non est singulariter ad hanc auenam uel ad hanc aquam, sed ad quamlibet indif-
ferenter; unde quamcumque primitus inueniret illam caperet. Et intentio naturalis uel
appetitus ignis ad calefaciendum non se habet modo singulari ad hoc calefactibile uel
ad illud, sed ad quodlibet indifferenter quod ipse posset calefacere; ideo quodcumque
sibi praesentetur, calefaceret ipsum; ergo etc.”
c Peter King, unpublished
18
BETWEEN LOGIC AND PSYCHOLOGY
difference between qualitatively indistinguishable substances unless we per-
ceive them relative to one another; nor can we tell whether a given object
is the same or different from one we saw previously, even for items that are
merely similar rather than indistinguishable. Such failures of discernibility
suggest that sensitive cognition does not reach the individual, but some
qualitatively more general level.
29
The singularity of sensitive cognition,
then, is due to neither its material composition nor its being intrinsically
singular.
Buridan offers an alternative original account of what it is to perceive
something as singular:
30
Let me therefore declare that something is perceived singularly in
virtue of the fact that it is perceived as existing within the prospect
of the person cognizing it. . .
Buridan is not (merely) saying that an object has to be present in the
perceiver’s sensory field to cause a perception. His point is more subtle:
the singularity of perception is a function of the object’s presence in the
perceiver’s sensory field. That is, the singularity of sensitive cognition does
not stem from its inherent nature or from some characteristic feature of the
object, but from the circumstances in which it occurs:
31
29
See for example DUI p.2 q.1 153.14–29, QSP 1.07 fol. 8vb, QDA (3) 3.08 263–274.
There is a particularly clear instance at QM 7.17 fol. 52va–b: “Si essent duo lapi-
des omnino similes in figura, in magnitudine, in colore, et sic de aliis, et successiue
apportarentur in tua praesentia, tu nullam uiam haberes ad iudicandum utrum se-
cundus apportatus esset ille idem qui primus apportatus fuit an alter. Et ita etiam
de hominibus si omnino essent similes in figura magnitudine et colore et sic de aliis
accidentibus; immo etiam hoc non solum ueritatem habet de substantiis immo etiam
de accidentibus: si enim essent albedines consimiles in gradu et essent in subiectis con-
similibus in figura magnitudine et caetera, tu non haberes uiam cognoscendi utrum
esset eadem albedo an alia quae tibi prius et posterius praesentaretur.”
30
QSP 1.07 fol. 8vb–9ra: “Dicam ergo, sicut magis uideri debet septimo Metaphysicae,
quod ex eo < aliquid >* percipitur singulariter quod percipitur per modum existen-
tis in prospectu cognoscentis. (Ideo enim Deus omnia percipit distinctissime ac si
perciperet ea singulariter: omnia clara sunt quia in prospectu eius.)” [*Reading aliq-
uid for aliud.] The same account is given in QDA (3) 3.08 298–303: “Ad soluendum
illas dubitationes, debemus ex septimo Metaphysicae uidere modum percipiendi rem
singulariter: scilicet quia oportet eam percipere per modum existentis in prospectu
cognoscentis. (Ideo enim deus quasi per modum singularem cognoscit omnia distinc-
tissime et determinate, scilicet quia omnia habet perfecte in prospectu suo per se.)”
31
QDA (3) 3.08 304–308: “Sensus ergo exterior quia cognoscit sensibile per modum
existentis in prospectu suo secundum certum situm, licet aliquando false iudicat de
situ propter reflexiones speciorum, ideo cognoscit ipsum singulariter uel consignate,
scilicet quod hoc uel illud. See also QSP 1.07 fol. 9ra: “Sensus autem exterior obiectum
suum apprehendit confuse, cum magnitudine et situ ad ipsum tamquam apparens in
c Peter King, unpublished