A New Age search for forgotten civilisations

There are not all that many books that look into the evidence supporting the existence of a sophisticated antediluvian civilisation so when I do discover one I generally read it with interest. However one of the problems that I find with these books is they tend to be written by new age scholars. While they resort to objective evidence at times, they end up spiralling down into very subjective proofs. This book, for instance, has a lot of subjective elements, such as apparent evidence for reincarnation and past lives. Unfortunately I am not the type of person that puts much faith in evidence of reincarnation that comes from somebody's meditative experience (though I must admit that I am guilty of that as well, though I try not to argue in favour of Christianity based on subjective experiences).
What I do like about this book and these types of books in general, are the pieces of objective evidence that are used to support the proposition of an advanced antediluvian civilisation. Personally, I believe that there was one, though it is more of a pet hobby of mine than the basis of my life's research. However such ideas do go to support my belief that humanity is not evolving but rather devolving.
This is one of the premises of this book: that civilisations fall because of their movement away from a spiritual reality to a more materialistic reality. Spiritual enlightenment and intellectual growth is replaced with the desire to have stuff, and our measure of importance is based upon the car that we drive and the suburb in which we live. Practicality is displaced by aestheticism. This reality is no more evidenced than by the existence of the BMW X5, which in my opinion is one of the most useless vehicles ever made. It is purely a status symbol and nothing more (and really, if you want a status symbol, get yourself a Rolls Royce). For those who do not know, the X5 is a Sports Utility Vehicle (SUV) which is, surprisingly, quite misnamed, because it is not all that useful. The reason that I say that is because while it looks like a 4WD, it is not a 4WD (they actually created a term called all wheel drive for these types of vehicle). Basically, the undercarriage is so low that if you take if off road (even onto the lawn) there is a danger that the entire undercarriage will be ripped out.
However, let us get back to the book for a bit. The issue I will raise is one of evidence. Basically, and this is coming from somebody who is legally trained, evidence is a fact, or something that can be based on a fact. Okay, we have expert evidence, which is the statement of opinion by an expert, and we also have the evidence of an eye-witness, which is a person's interpretation of an event that was witnessed, but we also have physical evidence, such as a knife, a gun, or even a corpse (though I don't think they drag corpses into the court room, they just show photographs). Now, while the object may be physical, the object itself may not actually say much, therefore the evidence needs to be interpreted. For instance, we present a blood stained knife, and it turns out that the blood in the knife is not from a human, but from a pig. We also have a corpse with stab wounds, but it turns out that the stab wounds came about because the deceased fell onto a pile of scrap metal, yet a blood stained knife and a corpse with stab wounds could also suggest that the victim was stabbed with a knife.
I raise the issue of evidence because that is what Lawton looks at in this book, and he presents us with a lot of interesting evidence. By bringing these things together he is able to suppose that this points to the existence of an antediluvian civilisation. For instance, the fact that the myth of a world wide flood appears in numerous cultures around the world, is supportive of such an idea. Other evidence suggests that coal and oil deposits found deep underground are also evidence of a world wide flood, while others will simply argue that this is the result of millions of years of geological movement. However, the problem is that we can only rely on this evidence (which in many cases is circumstantial) as there were no eye-witnesses that we are able to consult on this issue, much in the same way that there are no eye-witnesses that we are able to consult on what the Mayans were really up to when they made that calendar.