1 Objection 1: It seems that falsity is not in the senses. For Augustine says De Vera Relig. 33): If all the bodily senses report as they are affected, I do not know what more we can require from them. Thus it seems that we are not deceived by the senses; and therefore that falsity is not in them.
1 Ad secundum sic proceditur. Videtur quod in sensu non sit falsitas. Dicit enim Augustinus, in libro de vera Relig., si omnes corporis sensus ita nuntiant ut afficiuntur, quid ab eis amplius exigere debemus, ignoro. Et sic videtur quod ex sensibus non fallamur. Et sic falsitas in sensu non est.
2 Objection 2: Further, the Philosopher says Metaph. iv, 24) that falsity is not proper to the senses, but to the imagination.
2 Praeterea, philosophus dicit, in IV Metaphys., quod falsitas non est propria sensui, sed phantasiae.
3 Objection 3: Further, in non-complex things there is neither true nor false, but in complex things only. But affirmation and negation do not belong to the senses. Therefore in the senses there is no falsity.
3 Praeterea, in incomplexis non est verum nec falsum, sed solum in complexis. Sed componere et dividere non pertinet ad sensum. Ergo in sensu non est falsitas.
4 On the contrary, Augustine says Soliloq. ii, 6), It appears that the senses entrap us into error by their deceptive similitudes.
4 Sed contra est quod dicit Augustinus, in libro Soliloq., apparet nos in omnibus sensibus similitudine lenocinante falli.
5 I answer that, Falsity is not to be sought in the senses except as truth is in them. Now truth is not in them in such a way as that the senses know truth, but in so far as they apprehend sensible things truly, as said above Question 16, Article 2), and this takes place through the senses apprehending things as they are, and hence it happens that falsity exists in the senses through their apprehending or judging things to be otherwise than they really are.
The knowledge of things by the senses is in proportion to the existence of their likeness in the senses; and the likeness of a thing can exist in the senses in three ways. In the first way, primarily and of its own nature, as in sight there is the likeness of colors, and of other sensible objects proper to it. Secondly, of its own nature, though not primarily; as in sight there is the likeness of shape, size, and of other sensible objects common to more than one sense.
Thirdly, neither primarily nor of its own nature, but accidentally, as in sight, there is the likeness of a man, not as man, but in so far as it is accidental to the colored object to be a man. Sense, then, has no false knowledge about its proper objects, except accidentally and rarely, and then, because of the unsound organ it does not receive the sensible form rightly; just as other passive subjects because of their indisposition receive defectively the impressions of the agent.
Hence, for instance, it happens that on account of an unhealthy tongue sweet seems bitter to a sick person. But as to common objects of sense, and accidental objects, even a rightly disposed sense may have a false judgment, because it is referred to them not directly, but accidentally, or as a consequence of being directed to other things.
5 Respondeo dicendum quod falsitas non est quaerenda in sensu, nisi sicut ibi est veritas. Veritas autem non sic est in sensu, ut sensus cognoscat veritatem; sed inquantum veram apprehensionem habet de sensibilibus, ut supra dictum est. Quod quidem contingit eo quod apprehendit res ut sunt. Unde contingit falsitatem esse in sensu, ex hoc quod apprehendit vel iudicat res aliter quam sint. Sic autem se habet ad cognoscendum res, inquantum similitudo rerum est in sensu. Similitudo autem alicuius rei est in sensu tripliciter. Uno modo, primo et per se; sicut in visu est similitudo colorum et aliorum propriorum sensibilium. Alio modo, per se, sed non primo; sicut in visu est similitudo figurae vel magnitudinis, et aliorum communium sensibilium. Tertio modo, nec primo nec per se, sed per accidens; sicut in visu est similitudo hominis, non inquantum est homo, sed inquantum huic colorato accidit esse hominem. Et circa propria sensibilia sensus non habet falsam cognitionem, nisi per accidens, et ut in paucioribus, ex eo scilicet quod, propter indispositionem organi, non convenienter recipit formam sensibilem, sicut et alia passiva, propter suam indispositionem, deficienter recipiunt impressionem agentium. Et inde est quod, propter corruptionem linguae, infirmis dulcia amara esse videntur. De sensibilibus vero communibus et per accidens, potest esse falsum iudicium etiam in sensu recte disposito, quia sensus non directe refertur ad illa, sed per accidens, vel ex consequenti, inquantum refertur ad alia.
6 Reply to Objection 1: The affection of sense is its sensation itself. Hence, from the fact that sense reports as it is affected, it follows that we are not deceived in the judgment by which we judge that we experience sensation. Since, however, sense is sometimes affected erroneously of that object, it follows that it sometimes reports erroneously of that object; and thus we are deceived by sense about the object, but not about the fact of sensation.
6 Ad primum ergo dicendum quod sensum affici, est ipsum eius sentire. Unde per hoc quod sensus ita nuntiant sicut afficiuntur, sequitur quod non decipiamur in iudicio quo iudicamus nos sentire aliquid. Sed ex eo quod sensus aliter afficitur interdum quam res sit, sequitur quod nuntiet nobis aliquando rem aliter quam sit. Et ex hoc fallimur per sensum circa rem, non circa ipsum sentire.
7 Reply to Objection 2: Falsity is said not to be proper to sense, since sense is not deceived as to its proper object. Hence in another translation it is said more plainly, Sense, about its proper object, is never false. Falsity is attributed to the imagination, as it represents the likeness of something even in its absence. Hence, when anyone perceives the likeness of a thing as if it were the thing itself, falsity results from such an apprehension; and for this reason the Philosopher says Metaph. v, 34) that shadows, pictures, and dreams are said to be false inasmuch as they convey the likeness of things that are not present in substance.
7 Ad secundum dicendum quod falsitas dicitur non esse propria sensui, quia non decipitur circa proprium obiectum. Unde in alia translatione planius dicitur, quod sensus proprii sensibilis falsus non est. Phantasiae autem attribuitur falsitas, quia repraesentat similitudinem rei etiam absentis; unde quando aliquis convertitur ad similitudinem rei tanquam ad rem ipsam, provenit ex tali apprehensione falsitas. Unde etiam philosophus, in V Metaphys., dicit quod umbrae et picturae et somnia dicuntur falsa, inquantum non subsunt res quarum habent similitudinem.
8 Reply to Objection 3: This argument proves that the false is not in the sense, as in that which knows the true and the false.
8 Ad tertium dicendum quod ratio illa procedit, quod falsitas non sit in sensu sicut in cognoscente verum et falsum.