Anthropic Principle is well known that our existence in this universe depends on numerous cosmological constants and parameters whose numerical values must fall within a very narrow range of values. It is the philosophical consideration that observations of the Universe must be compatible with the conscious and sapient life that observes it. Anthropic Principle refers only to anthropic reasoning as originally formulated by Brendon Carter back in 1974. It states that this is a necessity, because if life were impossible, no living entity would be there to observe it, and thus would not be known. That is, it must be possible to observe some universe, and hence, the laws and constants of any such universe must accommodate that possibility.
