All human beings are blessed (or cursed) with rationality or the ability to think logically. It takes extraneous efforts to think illogically. This is true whether one is ruler of a country or a beggar on the street. Interestingly, even the mentally deranged humans are rational if not sensible. Their rationality is what keeps them alive in spite of not knowing what to do or what not to do. Rationality can disappear in human beings only when one is dead. Among our daily chores that fans the fire of rationality lies the eternal quest for meaning and purpose of life. All of us, at one time or other, must have asked these questions to ourselves in our moments of solitude. Most of us do not reach any conclusion or get an answer in our own lifetimes but we are destined to continue the search like a perpetual machine.
Ancient India was rich in material wealth but it was much richer in terms of spirituality and knowledge. Our contribution to the world body of knowledge far outweighs our accumulated wealth of gold, silver and diamonds. Several of our ancient concepts about life and living have stood the test of time. Among such gems of ancient wisdom, I would place the theory of rebirths at the very pinnacle. I am yet to come across any alternate theory that satisfies my rationality about logic of life in the midst of all the joy, sorrow, sufferings and pain. In the present world of uncertainty in all spheres of life, there is no better theory that can give us reason for hope. A brief look at the concept of God is a must before we can proceed.
Concept of GOD
There are many who strongly feel that there is no need for anything like God. And there are others who see God in everything. Let us put this in a different way. If 50,000 sets of alphabets in any language are dropped from a height of say 10,000 feet, there is a definite probability (greater than zero) of getting them arranged into one of the epic works in that language. For example, if sufficient sets of Sanskrit alphabets are dropped from the sky there is a distinct possibility of getting them arranged into the form of 'Meghaduta'. People who do not feel the need to have any form of God believe in such infinitesimally small probabilities for the proper functioning of everything in this universe. There are so many imponderables and uncertainties in this universe that no rational human being can rule out the existence of an unknown unifying force behind all that we see or perceive. There is so much of logic, control and complexity in each and every thing we see around that it is impossible to believe in the absence of something super natural. In fact the choice is between a Gambler Or Designer, but there is something or someone for sure.
The concept of God can be best described in terms of its tangible and intangible attributes. On a tangible plane, we find certain common features in everything in this universe. The three indispensable features are movement, cycle and symmetry. Be it materials, energy, events or phenomena, these features show up their inevitability in one form or another. Everything physical is moving of its own and everything is cyclic and symmetric. If God is to be described in easy terms, I would call Him as a 'Cyclo-Symmetric Prime Mover'. On the intangible plane, the most striking feature is that of His unflinching partiality towards righteousness. Mother Nature exhibits a distinct positive reservation in favor everything that is right. Our conscience keeps reminding us of the right way and I am sure this is true of even the worst criminals or wild animals if they are not drunk or drugged.
Logic of Rebirths
Man is just one among the millions of living kind and any theory that gives him undue importance is definitely misplaced. Perhaps the centrality of mankind is prevalent because we consider Man as the best of God's creations. This is again wrong if we bother to look around at the vast diversity of living beings and non-living things that surround us. The best we can conclude is about an evolutionary cycle in nature with Man somewhere on the top. Since nothing can be differentiated at sub-atomic levels, it is only logical to include even non-living matter at the other end of the evolutionary cycle. Each of present day humans must have started his/her evolution at a non-living plane and over millions of years developed into a 'fifol'. Since then it must been the natural cycle of lives and deaths as one or another of the living beings. There is a semi-scientific belief that human body looses 21 grams instantaneously on death and somewhere some fetus gains that weight. Then there have been numerous Kirlian photographic observations about 'something' that leaves our body on death. All these point to only one direction ie. about the existence of a natural cycle of births and deaths which is both cyclic and symmetric as all other natural processes are.
The logic of rebirths is highly accentuated if we look at it from spiritual or moral points of view. In the world around us of so much uncertainty, we find some people who have everything going their way and others who stand to lose in everything they venture. We have children born with highly painful cancer and virtuous parents suffering their lifetimes with mentally retarded children. Then we have criminals and evil men succeeding in life after committing all types of horrible crimes. Such vagaries of nature can be explained only in terms of a cycle of lives based on performance during an earlier life. Our theory about God's unflinching encouragement for righteousness may not hold good at all times for all people. Sometimes we see good people fail in doing good things and bad people succeed in doing bad things. All humans are good by nature and it is the circumstances & desires that make some of them evil at times. Remember what Mahatma Gandhi once said "When I despair, I remember that all through history the ways of truth and love have always won. There have been tyrants, and murderers, and for a time they can seem invincible, but in the end they always fall. Think of it... always." Thus an affirmative logic in favor of truth is a must to keep our hopes alive and that is exactly what the concept of rebirth provides.
However much we deliberate on these aspects of life, we can only reach the rational conclusion about the essentiality of rebirths. Those who do good will keep on evolving into higher forms of life and those who opt for the evil path will go down the evolutionary cycle. Repentance and confession are mere humbug. We find heaven and hell in our own midst. Those who do evil shall pay for it this life or the next or the next next. And that exactly is the perfect logic that will satisfy our rationality.