This post is written with Fr Andrew in mind particularly, but not, of course, exclusively.

In his short work, De Operationibus Occultis Naturae, St Thomas is discussing why bodily things, whether animate or inanimate, have the properties they do. He says there is a distinction between properties that can be explained simply by the properties of the elements of which the things are composed, and other properties which can't be so explained. As examples of the first kind he gives a stone moving downwards 'because the element of earth predominates in it', and metals cooling things 'because of the property of water'; metals supposedly containing water. As examples of the other kind of property he gives magnets attracting iron and medicines 'purging certain humours from certain parts of the body'.
These latter properties, he says, can't be explained by appealing to the elements of which the things are made, since neither earth, air, fire nor water attract iron or purge unpleasant humours. From which he concludes, 'therefore it is necessary to reduce these actions into higher prinicples', i.e. postulate causes higher than the elements, to explain them. The higher principles, he says, must themselves be bodily, since 'what makes must be similar to what is made', and as the immediate cause of the cycle of generation and corruption, they must not be something completely immobile: these higher principles, of course, are the corpora caelestia (this is not to exclude the yet higher causality of the angels, nor, evidently, the immediate activity of the first Cause in all change.) So he argues that it is under the influence of these superior, incorruptible bodies at the moment of generation, that the generated substance has properties that exceed the virtue of the elements within it.
What I should like to ask is whether the original distinction can be accepted: that is, the distinction between properties that can be explained simply in virtue of a thing's elementary parts and others which can't But this also raises the question of what the modern equivalent of the 4 elements is: presumably not the elements of the Periodic Table, if these have kinds of particle in common.

Malum meum

I messed up the organisation. I apologise. Proper posts to follow.