Looking back into the past the nineteenth-century historian finds his sight speedily striking a mist and at last plunging into inky darkness. Bound down in fact by the influence of a ridiculous dogmatism which allows only some six thousand years for man's life on earth, he is unwilling to accept the old chronologies of the Egyptians or Hindus, and, while permitting the assumption of vast periods for geological changes, he is staggered by a few millions of years more or less when they are added to the length of time during which humanity has peopled the globe. The student of Theosophy, however, sees no reason why he should doubt the statement made by his teachers on this subject. He knows that the periods of evolution are endless. These are called Manvantaras because they are between two Manus, or, two men.
These periods may be called waves whose succession has no cessation. Each grand period, including within it all the minor evolutions, covers 311,040,000,000,000 human years; under a single Manu the human years come and go, 306,720,000 in number, and the lesser yugas — or ages — more immediately concerning us, comprise of solar years 4,320,000. During these solar revolutions the human races sweep round and round this planet. Cave-dwellers, lake-dwellers and those of a neolithic or any other age appear and disappear over and over again, and in each of those we who now read, write and think of them were ourselves the very Egos whose past we are trying to trace.
But, going deep into geological strata, the doubt of man's existence contemporaneously with the plesiosaurus arises because no fossil genus homo is discovered in the same stratum. It is here that the theories of the Theosophist come in and furnish the key. Those hold that before man developed any physical body he clothed himself with an astral form; and this is why H. P. Blavatsky writes in her Secret Doctrine: "it teaches the birth of the astral before the physical body, the former being the model for the latter." At the time of the huge antediluvian animals they absorbed in their enormous bodies so much of the total quantity of gross matter available for frames of sentient beings that the astral man remained without a corporeal frame, as yet unclothed "with coats of skin." For this reason he could exist in the same place with those huge birds and reptiles without fear. Their massive proportions inspired him with no terror, and by their consumption of food there was no lessening of his sustenance. And, therefore, being of such a composition that he left no impression upon mud or plastic rock, the death of one astral body after another left no fossil and no mark to be unearthed by us in company with the very beasts and birds which were his contemporaries.
Man was all this time acquiring the power to clothe himself with a dense frame. He threw off astral bodies one after another, in the ceaseless pursuit, each effort giving him a little more density. Then he began to cast a shadow, as it were, and the vast, unwieldy animal world — and others as well — felt more and more the draughts made upon it by the coming man. As he thickened they grew smaller, and his remains could not be deposited in any stratum until such time as he had grown to sufficient hardness. But our modern anthropologists have not yet discovered when that was. They are ready enough to make definite statements, but, learned as they are, there are surprises awaiting them not so far off.
While, therefore, our explorers are finding, now and then, the remains of animals and birds and reptiles in strata which show an age far greater than any assigned to the human race, they never come upon human skeletons. How could man leave any trace at a stage when he could not press himself into the clay or be caught by soft lava or masses of volcanic dust? I do not mean, however, to say that the period of the plesiosaurus is the period of the man of astral body devoid of a material one. The question of exact period may well be left for a more detailed account; this is only to point to the law and to the explanation for the non-appearance of man's remains in very early geologic strata. But the Theosophic Adepts insist that there are still in the earth bony remains of man, which carry his first appearance in a dense body many millions of years farther back than have yet been admitted, and these remains will be discovered by us before much time shall have rolled away.
One of the first results of these discoveries will be to completely upset the theory as to the succession of ages, as I may call it, which is given and accepted at the present time, and also the estimation of the various civilizations that have passed from the earth and left no trace except in the inner constitution of ourselves — for it is held that we are those very persons, now in different bodies, who so long ago lived and loved and died upon the planet. We began to make Karma then, and have been under its influence ever since, and it seems fitting that that great doctrine should be taken up at another time for a more careful examination.