The second Hermetic principle is that of correspondence.  This principle is best known by the sayings "as above, so below" and  "as within, so without".    What this means is that there are certain universal laws that govern all nine dimensions of existence.  While these laws exist on all levels, they manifest in different ways depending on the nature of that level or dimension.  
    For the most part, these laws flow from the higher dimensions to the lower.  A man made law of the third dimension may have some effect on the second dimension, but no effect on higher dimensions.   No matter how much man tries to ignore the laws from above and make his own, he cannot change them.  Universal laws can only be changed from a higher dimension.  Congress cannot pass a law to cancel gravity, but God can since God is the higher dimension.
    Even just within the third dimension we see some of this principle in the way that an atom looks and behaves much like a  tiny solar system.  And galaxies are much like giant solar systems.  And our spiritual soul functions much like a material brain, but on a spiritual level rather than a material one.
    SInce part of this law is that things that happen on the material level must first happen on the spiritual level, it is possible for someone who knows how to see and interpret the signs, to see into the future.  SInce physical objects don't exist in the spiritual worlds, your not going to see a tree grow in a spiritual dimension, but you will see complex arrangements of geometric symbols in light.  With the knowledge of how to interpret those symbols, you would recognize the tree before it actually grows.  For those who haven't developed the ability to see into the spiritual dimensions, dreams, visions and signs help guide us from above until we can.