Remembrance, we shall see later on, is preserved in the cosmic Memory, but until the soul has readied a sufficient development, it cannot summon it forth, and even could it do so, it would succeed in leaving its impress on the brain only when the physical, the astral, and the mental bodies have submitted to a process of purification which harmonises[78] them and binds them closely together. Then only does man know that Reincarnation is true, and takes place on earth until this latter passes into a slate of obscuration,[79] or, at all events, until the development of the soul enables it to utilise for its evolution some environment on the planet, other than the physical one.[80] We shall be told that we are now proving what we before denied. No, we are simply stating an exception which happens in very few cases and only then to the pioneers of the race--an exception which is nothing but an apparent one and finds its place in the progressive order which unifies all the beings in the planetary chain to which we belong. FOOTNOTES: [Footnote 41: Each part possesses in a potential state the properties of the whole.] [Footnote 42: The kingdoms that are invisible to physical sight are as interesting as those we see, but we have no occasion to speak of them here. Logic compels us to acknowledge them until the time comes when human development enables them to be discovered and affords direct proof of their existence.] [Footnote 43: We do not mean to affirm that evolutionists have not committed serious errors in their theory of development. But the law they have set prominently forth is one of the fundamental expressions of the working of God in the Universe.] [Footnote 44: The vibratory impressions that constitute the memory of the Universe. See in Chapter 4, the final _Objection._] [Footnote 45: See _L'or et la Transmutation des metaux_, by Tiffereau.] [Footnote 46: Such as the one with the magnet which, if too great a weight is suspended to its armature, loses strength, and this it only regains by degrees when "fed" with successively stronger charges. A steel spring that has borne too great a weight loses strength, and may break if subjected anew to the same weight that "fatigued" it. Pieces of iron break after being "fatigued" by a weight they easily carried before. Professor Kennedy made very useful experiments regarding the "fatigue" of metals at the time when metallic bridges were continually breaking, thus causing great perplexity in the engineering world.] [Footnote 47: There has been much discussion as to the causes of Evolution.