Analytical truths are by definiton are true and independent of any emprical evidence or observation. So let me tell it more simple: we accept they are true. Saying they are true without depending on anything or this is basic stuff doesnt make them true. Let me ask a simple question, why do we define them true without dependence on anything. You can not answer it becuase this is the limit of where our comprehension stretch out.

I said we cannot find anything to be the base of our morals except religion. And I especially state that you have to believe them, not logically prove them to take them as your base for morals. You can take anything as your premises, like religion or analytical truth or synthetic truths; its upon you. To me the most useful one is to take analytical truths as base.