Edgar Cayce's Dream Dictionary

So I ran across this the other day, and was curious. This guy, Edgar Cayce, was/is a dream interpreter, and a supposedly good one at that. I've been really interested in dream interpretation lately, and I've always kind of shrugged these kinds of things off, because I feel like the best person to interpret your dreams is yourself, and there probably are few, if any, universal dream symbols.

This dictionary, however, gives many different observed meanings for common dream symbols. However, some of them greatly contradict what I've learned. An example would be the appearance of a dog in your dream. I see dogs as symbolizing loyalty and friendliness. This is what Cayce says about them (it's kind of contradictory to what I was thinking):

Dog 1. a nature or disposition that may not always be trusted (294-87). 2. that which is faithful and unfaithful (288-17). 3. that which is friendly or, if aroused, an enemy (294-97). 4. things going downhill-going "to the dogs" (294-97). Other possibilities: 1. aggressiveness. 2. Instinctive knowledge. 3. obedience.
Some of the things he says, however, make sense to me.

So what are your thoughts on dream interpretation dictionaries? Do you think that there are many universal symbols, a few, or none? Do you think this guy is a genius, or full of crap?