I wrote one short summary of this as follows: ‘The starting point may be different in each case, but what all three traditions have in common is their goal, the contemplation of heavenly things. To illustrate this point: we can say that ‘iconographic’ tradition, which we have been referring to so far, portrays Eschatological Man; the baroque portrays Historical Man, that is fallen man; and the gothic portrays the transition between the two by degrees – it is the art of pilgrimage. So in the dynamic of prayer Eschatological (‘iconographic’) art, takes directly to heaven, it starts and finishes there, as it were. The baroque on the other hand starts in a fallen world, but from there directs our thoughts to heaven.’
Stylistically, the gothic represents a steadily greater naturalism fused to a substrate of the iconographic style. So the earlier gothic art looks very similar to the iconographic. The degree of naturalism is greater than what preceeded it, but there is nothing un-iconographic about that. Even in the Eastern Church, there are iconographic forms that are naturalistic (for example those painted in the Greek Church about 1000 years ago. In many ways early gothic art could as easily have been seen as just another Western variant. Apart from his depiction of saints in profile and an occasional use of natural perspective, the great Sienese artist of the 13th and early 14th centuries, Duccio would be in this category. In that sense, his art occupies the upper region of the gothic spire. Artists such as Fra Angelico and, even more so, Van Eyck have more naturalism and so sit closer to earth. This doesn’t mean that the art of Fra Angelico or Van Eyck is an inferior form. As I mentioned, the goal of all Christian liturgical art is the same, to raise us up to the contemplation of heavenly things. It is the degree to which the art does this characterizes its value. I would make the same point in regard to a comparison between the iconographic and the baroque. I have heard many people say that they feel that the iconographic is a superior art form because it portrays the heavenly realm. I would say not at all. Some may personally relate to one form over the other, but good baroque art and good iconographic are potentially as powerful in their own ways in achieving the same end.
Incidentally, observation of nature was as important to Van Eyck as it was to the baroque masters. The difference in style arises not from the degree of naturalism, but from a difference in the substrate to which that naturalism is attached. Unlike Van Eyck, the training of the baroque masters required them to draw plaster casts of Greek and Roman statues. The naturalism of the baroque masters, therefore is fused to a classical rather than an iconographic form. This is what causes the dislocation in style between Van Eyck and what followed him.
Anyway, here are some Duccio paintings contrasted with Van Eyck's Ghent Altarpiece (I think we’ve seen plenty of Fra Angelico in recent weeks!). We can see how Van Eyck painting in the 15th century uses shadow and perspective freely.
The other articles in the series are:
The Symbolism in the Content of Fra Angelico's Frescoes
Fra Angelico's Theology of Light
