No, collective consciousness is no more needed to explain symbols than it's needed to explain how we all know 2+2=4. It makes objective sense for, for example, a circle to symbolise eternity, because unlike other shapes, if you followed its circumference looking for a point at which it changes direction, you would look forever and not find one. Symbols share a property with the thing they represent, that's all.
Have to agree with this really... symbology is derived from a concept that made sense in the first place.
Note that even something like say... an ankh, has a rounded part to represent a cycle of life and death, the curvature can even be interpreted to be how yeur lifespan works, young and old at the weaker points when yeu're limited in capacity usually, and the larger section when yeu make the majority of yeur life's accomplishments.
Many cultures used writing of a symbolic form, with many different forms of hieroglyphics, pictorials and so on. Drawing a picture of a bison on a cave wall is still a symbol of depicting the concept, though the interpretation can be taken as either food, strength, courage, fear, or several other traits which may've been associated with the image at the time.
We need no collective consciousness or anything else to understand that "cats think they are gods", and therefore the cat can symbolize many things, depending on how one interprets their traits determined by one's culture. Cats are actually a great example of this, as some cultures worshiped them, others considered them demonic and evil. Obviously there wasn't any collective consciousness there, yet in both cases they stood in as a proxy of something else, which is basically whot a symbol is.
A *REALLY* good one is the number 3; not the shape of the number itself, but the actual NUMBER 3; many cultures considered 3 vastly important, either for good or ill, and most counting systems were actually in base-3 rather than base-10 until relatively recently. How one symbolized such a nearly-universally accepted important number though greatly changed between cultures... sometimes yeu have a circle with 3 outcropping lines or figures, roughly 120 degrees apart; other times yeu have a triangle, and sometimes more like the roman numeral III, or 3 dots in a variety of patterns, there's many ways of depicting this, yet 3 is almost always considered an important number. If it's so important to so many cultures, why then do they not depict it in the same manner of symbology every time?
I can only conclude that the symbol is derived from the concept, and not the other way around.
EDIT: (oops forgot my main point, pardon my entpness ^.~ )
That being said, symbols *DO* hold power... not because of the symbol itself though, but because of the concept behind the symbol. People believe in ideas; sometimes these take the shape of something very obviously symbolic such as a shape or glyph or whotever; other times they manifest as a person themselves. Check the greatest leaders in history - a leader rarely ever *DOES*, they enable *OTHERS* to do through the power of their symbolism. Napolien wasn't the greatest military planner ever (though he was pretty good and actually used artillery properly when noone else was doing so at the time), but he stood as a symbol to his people at the time of power and victory, which allowed them to do better than they would've otherwise. Hitler was a HUGE symbol to germany at one point, by acting as a focal point, a nexus of strength to an entire people. People just find it easier with something to rally behind, be it a concept, a person, a mantra, or a symbol; they all retain the same essential components though and are essentially the same thing, in a variety of forms.
Symbols don't directly have power though. The concepts behind them do; the symbols just make it easier for people to understand the concept and rally behind it is all.
