"I THINK therefore I AM." Does it mean that if I don't think I don't exist? Thinking is about making sense from what we experience, describing the environment we live in. Thinking is a process of organizing, assessing and systemizing reality. It is important but is it truly the only valuable function of a human being? Why do we have bodies if we supposed only to think? Body is actually doing a lot of life-important things all the time without any involvment of intelligent mind. It is breathing, pumping blood, changing cells, digesting the food, guarding our safety. Is there no value in these functions?
We got so attached to this idea of thinking that the possibility of not doing it scares us. Or rather only a part of us is scared: the little, thinking mind. We let it control us; it became the ruling factor in our existance and will not yield to anything. It is constantly canvasing and lobbing for itself emphesizing its own importance. That's why it is so difficult "to stop" thinking.
Meditation is about looking for some other important part of us worth paying attention to. Meditation is a practice that allows regaining the proper dinamic in life. It will not make you dumb and indifferent. Contrary it will allow you to feel without being scared of the feeling, it will help you to use a tool of intelligent mind when you really need it; it will help you to be present in your own life, present with your family, your friends, at work and on holiday when your body is actually there.
I AM does not need justification.