One of the trickiest parts of studying apocalyptic literature is interpreting the imagery and symbolism used. This will be the first of three parts dealing with apocalyptic imagery and numerology in which we will make some general observations and also deal with a few specific passages.
I think that one of the most important things to consider when reading texts like Daniel 7-12 is that the meaning of the symbols has two components; sense and referent. Referent is the object that the symbol stands for (e.g., the four hybrid/distorted beasts in Daniel 7 stand for four kingdoms). The sense is the interpretation of the referent that the symbol provides (more on this later). Unfortunately, within the Evangelical church I think that the sense has been a bit ignored. Most lay people (and more than a few pastors) come to a text like Daniel and have lots of questions about the historical referents but not many about the sense. Apocalyptic texts get treated as a code that we need to unravel. That, though, runs into two problems. One is that not every symbol has a clear historical referent. Take the wind in 7:2 as an example. The wind symbolizes God's power, that is the sense of the symbol, but I don't see what clear historical referent it has. The second, and the more obvious problem is that by focusing on just the referent you're missing out on what is in my opinion the more important aspect of meaning, the one from which we can draw out theology, the sense, or God's interpretation of history.
How do we know the sense of the symbols? They're very foreign to us because they come from another culture. Thus to understand them we need to understand the culture and the genre of apocalyptic. Here, nothing but hard work will suffice. The vast majority of Jewish apocalyptic literature did not make it into the canon (in fact Daniel is the only OT text that can formally be called an apocalypse, though portions of Zechariah and Isaiah are precursors to the genre that would later develop). Thus we have to do some reading outside of the Bible to get a better sense of how it was used. Probably the most helpful for comparisons with Daniel is 4 Ezra which is found in 2 Esdras 3-14. Fortunately, since it is part of the Apocrypha, you can find it online for free in the NRSV. If you want to read more Jewish apocalyptic, you should probably purchase a copy of the Pseudepigrapha, now thankfully published in softcover for half of the price of the hardcovers! Reading broadly within the genre will help you get a feel for how symbolic imagery is used. A second step would be to get your hands on a good introduction to apocalyptic literature. I personally found The Apocalyptic Imagination: An Introduction to Jewish Apocalyptic Literature by John Collins to be extremely helpful. This will help you get a general lay of the land when it comes to Jewish apocalyptic and does some of the comparative work for you. It's very helpful for getting a macro level look at what's unique or not unique about each apocalypse. Finally when you study the specifics of any passage you must have at least one of (preferably both) the following commentaries: Daniel: A Commentary on the Book of Daniel by John Collins and Word Biblical Commentary Vol. 30, Daniel by John Goldingay. They wade through all of the relevant data and lay out clearly the background and meaning of the symbols. As a general comment, while both Jewish sources and other ANE (in particular Canaanite) sources can be the source of the sense of any given symbol, priority must be given to prior biblical usage (which, as one would expect, often is related to its sense in non-Jewish ANE sources).
Earlier I mentioned that the four beasts stand for four kingdoms. That is their referent. What is their sense? First we must consider that crossbreeding animals was outlawed in the Torah so at minimum we can say that they symbolize something unholy. When you look more deeply into the symbolism, though, it seems that to Jews the fact that these beasts are hybrid would suggest demonic control. Thus from the sea (the place of opposition to God) we have four kingdoms that oppose God's people that are demonic, they embody evil. The fourth kingdom in particular is so grotesque and hence evil that it can't even be described.
In our next post we will look at the sometimes multivalent nature of apocalyptic imagery as well as discuss how the literature speaks to us today.