But although there are several cases on record in which some well-remembered scene has thus come through from one life to another, a considerable development of occult faculty is necessary before an investigator can definitely trace a line of incarnations, whether they be his own or another man's. This will be obvious if we remember the conditions of the problem which has to be worked out. To follow a person from this life to the one preceding it, it is necessary first of all to trace his present life backwards to his birth and then to follow up in reverse order the stages by which the Ego descended into incarnation.
This will obviously take us back eventually to the condition of the Ego upon the higher levels of the mental plane; so it will be seen that to perform this task effectually the investigator must be able to use the sense corresponding to that exalted level while awake in his physical body--in other words, his consciousness must be centred in the reincarnating Ego itself, and no longer in the lower personality. In that case, the memory of the Ego being aroused, his own past incarnations will be spread out before him like an open book, and he would be able, if he wished, to examine the conditions of another Ego upon that level and trace him backwards through the lower mental and astral lives which led up to it, until he came to the last physical death of that Ego, and through it to his previous life.
There is no way but this in which the chain of lives can be followed through with absolute certainty: and consequently we may at once put aside as conscious or unconscious impostors those people who advertise that they are able to trace out anyone's past incarnations for so many shillings a head. Needless to say, the true occultist does not advertise, and never under any circumstances accepts money for any exhibition of his powers.
Assuredly the student who wishes to acquire the power of following up a line of incarnations can do so only by learning from a qualified teacher how the work is to be done. There have been those who persistently asserted that it was only necessary for a man to feel good and devotional and "brotherly," and all the wisdom of the ages would immediately flow in upon him; but a little common-sense will at once expose the absurdity of such a position. However good a child may be, if he wants to know the multiplication table he must set to work and learn it; and the case is precisely similar with the capacity to use spiritual faculties. The faculties themselves will no doubt manifest as the man evolves, but he can learn how to use them reliably and to the best advantage only by steady hard work and persevering effort.