Appendix 9.

(495) [St. Thomas' illustrated phantasms]

St. Thomas often uses the phrases, illustrari phantasmata, abstrahere phantasmata, to indicate two operations of the acting intellect (S.T. I, q. 79, art. 4; I, q. 85, art. 1, ad 4). What is the proper meaning of the metaphorical expression, illustrari phantasmata? If I am not mistaken, it corresponds, as I have suggested, to universalisation, that is, the operation which forms ideas when phantasms present themselves, and thus enables sensile things to be understood. Undoubtedly illustrating them is a very happy way of describing the way our intelligence adds the idea of being to felt things which alone makes them intelligible, or clear, to the intellect. However, some passages of Aristotelian philosophers could render this interpretation doubtful, and lead us to believe that the two phrases do not always possess a clear, precise meaning. It would even seem that the phrase to abstract is often used to indicate the universalisation of ideas.

Nevertheless, careful consideration would seem to show that the passages in question can be given an adequate meaning. For example, this is how St. Thomas describes the two operations, illustration and abstraction: 'The phantasms are illuminated by the acting intellect, and the intelligible species abstracted from them by power of the acting intellect. They are illuminated by the acting intellect because its power is such that what is intelligible is abstracted from the phantasms, just as the sense part gains in strength from being joined to the intellect. The acting intellect abstracts the intelligible species from the phantasms in so far as, through the acting intellect, we can consider the nature of various species stripped of their individuality, in accordance with the likenesses informing the possible intellect' (S.T., I, q. 85, art. 1, ad 4).

What does St. Thomas mean when he says that the sense part gains in strength (efficitur virtuosior) through being joined to the acting intellect, and moreover gains the power which renders the phantasms capable of undergoing the abstraction that provides the intelligible species, or ideas, of things? It is not difficult to recognise the nature of this power if we know what enables us to abstract the specific natures of things (the ideas), and I think I have shown what this is. As I said, the sensations or images (phantasmata) are united to the idea of being and to judgment on the thing's subsistence. In this way, intellectual perception is determined according to the individuals perceived by the sensations (phantasmata). The specific ideas of things are drawn precisely from the intellective perception (through a twofold type of abstraction: first, that by which the judgment indicating real things is removed; second, that by which individual conditions are set aside) in order to arrive at universal, pure and separate ideas. It seems clear that St. Thomas' illustrated phantasms correspond perfectly to what I have called intellective perceptions.