This is your true essence of their sets, which is remembered that there is in this life yet something is not done, but it is very important, without which life will be spent in vain. We now can say exactly what the outside world We do not know. We do not know him. We are limited in its perception of its authorities collecting information. We know the world only through its effects on our hearing of sight, smell, etc. Here, you want a little clarification on the case. Hearing. Y our auditory organ is a membrane that separates us from the outside world and what lies beyond that boundary, we do not know.
We can only speculate on the limited AS then that is outside of us to influence us. In this case, the pressure fluctuations in the membrane. With all the diversity that may surround us, we can only accept what we are allowed to take our limited senses. What follows from this? What the whole world is in us. This is what causes us an external stimulus, and how it relates to. All information that we get - initially limited to the receipt and further distorted, though the same filter of our ego, which is absolutely do not want to show something beyond their own interests. But the question is, sometimes we feel that something extra and it can not explain. What is it? Another organ of perception? Back to our 'homo global'. We can see that everything evolves from simple to complex.