Cause and Effect

By giving a look to the book The Questions of Life I found a curious explanation of the existence itself. It says: "We assume that everything must have a "suficient reason" for xisting, to follow Leibniz's terminology. Well if everything has a cause, should there not also be a Cause of Everything?". I started to think about this explanation and reflected a long time about it. Since old times, people have always said that there must be a cause for everything. I also believe that there is a cause for every effect. I mean, inside of our society we call it a law, and a law is something that is proven, something you can experiment on and it will give you the same results. All this reasoning gave us tools to think that the Universe had to have a cause, and I agree with this reasoning, unless the universe is the cause an the effect hasn't ocurred. My rationality pushes me toward the first reasoning, but I can't forget or maintain apart the other reasonings, because if the Universe had a cause and we are part of the effect that means we share things in common and all our reasoning and basically everything that exists produce the totality of the effect. Causes have a purpose, that forces me to think that if there was a purpose we are part of, then there is somebody who is seeing all this, or was before all this. I believe we are not alone in the world and that there was other bodies who might have caused what was caused or see it. I believe our existence and the Universe existence is linked to somebody else's or somewhere else's existence.