I previously noted a weakness in the otherwise exemplary use that Robert Pippin makes of Aristotle in his groundbreaking reading of Hegel. Pippin wants to emphasize the radical novelty of Kant’s claims about the active role of human intellect in the formation of what we take as reality. This drives him to make the seriously wrong claim that Aristotle views intellect as purely passive, or receptive of pre-given forms. This is a complicated subject, but I think the beginning of a reasonable interpretation is to recognize that our ability to think is neither purely passive (merely receiving the given), nor purely active in the sense of having no objective dependencies, or in the sense of arbitrary choice.

Aristotle suggests a kind of analogy between sense perception and intellect. His account of sense is oriented toward explaining the relative objectivity of ordinary sense perception. But context is all-important here. If Aristotle bends the stick rather far in the direction of realism, this needs to be understood as a counterbalancing response to Plato’s sometimes extreme distrust of the deliverances of sense.

Pattin says that for Aristotle, it is necessary to posit an agent intellect because sensible intelligibles do not exist in act outside the soul. Any existence of sensible intelligibles outside the soul is only potential.

There was a major debate among the Latin scholastics about the passivity or activity of sense. One view does argue that there is no such thing as an active component in human sense perception, that it is entirely passive. But the other view sharply objects to this. Pour l’histoire du sens agent by A. Pattin (1988) collects many of the Latin sources for this dispute. I am not so bold as to offer my own translations from the Latin, as I occasionally do with French. But I wanted to at least briefly skim the surface of this extensive debate on the existence of active sense.

Pattin notes that Albert the Great already catalogued many views concerning the causal role of the sensible object in relation to the human sensitive faculty. Some authors assigned the active role in visual perception to light. For others though, including Augustine, it is the activity of the soul, in reaction to the experience of the sensible object, that forms the cognitive content of sensation “from its own substance”. Pattin says that for Augustine, it is absolutely impossible for the spiritual soul to be passive in relation to sensible realities, because the inferior cannot in any way act on the superior. I would note that in this Augustine follows Plotinus.

Pattin says that Aquinas accepts a non-Augustinian view of sense perception as categorically passive. For him sensibles are found in act outside the soul. But he argues against giving much weight to the analogy between sensation and intellect, because he wants at the same time to defend the existence of an active intellect within the human soul. In itself, the issue of active sense is not very important for him.

This understanding of the significance of positions for and against the analogy between intellect and sense is very far from the way Pippin presents it. For both Aquinas and Pippin, the analogy is an argument from a claimed passivity of sense to the passivity of intellect. For Aquinas, the truth is that sensation is passive while thought is not. But for a number of important medieval and Renaissance thinkers, both our sense perception and our thought have an active component, and the analogy supports this.

There was a particularly influential debate on this subject between Bartholomew of Bruges (ca.1286-1356) and John of Jandun (ca. 1285-1328). Bartholomew is believed to have written three treatises against the notion of active sense, of which one survives. John on the other hand defends the analogy of sense and intellect, and uses it to argue from the existence of active intellect to the existence of active sense. An intermediate position is argued by John Buridan (ca. 1301-1360), who was also an important participant in the debates about nominalism and realism. John of Jandun’s position was defended by numerous Italian Aristotelians — including Taddeo de Parma, Mathieu de Gubio, Gaetan de Thienne, and Agostino Nifo, who like John of Jandun have been labeled as Latin “Averroists”. It was discussed by other very non-Thomistic Aristotelians like Pietro Pomponazzi and Jacobo Zabarella. The intermediate position of Buridan was meanwhile taken up by his students, like Nicolas Oresme and Marsilius of Inghen.