These considerations will greatly simplify our ideas of life. We have no longer to consider two forces, but only one, as being the cause of all things; the difference between good and evil resulting simply from the direction in which this force is made to flow. It is a universal law that if we reverse the action of a cause we at the same time reverse the effect. With the same apparatus we can commence by mechanical motion which will generate electricity, or we can commence with electricity which will generate mechanical motion; or to take a simple arithmetical instance: if 10/2 = 5, then 10/5 = 2; and therefore if we once recognize the power of thought to produce any results at all, we shall see that the law by which negative thought produces negative results is the same by which positive thought produces positive results. Therefore all our distrust of the law of growth, whether shown in the anxious endeavour to bring pressure to bear from without, or in allowing despair to take the place of cheerful expectation, is reversing the action of the original cause and consequently reversing the nature of the results. It is for this reason that the Bible, which is the most deeply occult of all books, continually lays so much stress upon the efficiency of faith and the destructive influence of unbelief; and in like manner, all books on every branch of spiritual science emphatically warn us against the admission of doubt or fear. They are the inversion of the principle which builds up, and they are therefore the principle which pulls down; but the Law itself never changes, and it is on the unchangeableness of the law that all Mental Science is founded. We are accustomed to realize the unchangeableness of natural law in our every day life, and it should therefore not be difficult to realize that the same unchangeableness of law which obtains on the visible side of nature obtains on the invisible side as well. The variable factor is, not the law, but our own volition; and it is by combining this variable factor with the invariable one that we can produce the various results we desire. The principle of growth is that of inherent vitality in the seed itself, and the operations of the gardener have their exact analogue in Mental Science. We do not _put_ the self-expansive vitality into the seed, but we must sow it, and we may also, so to speak, water it by quiet concentrated contemplation of our desire as an actually accomplished fact. But we must carefully remove from such contemplation any idea of a strenuous effort on our part to _make_ the seed grow. Its efficacy is in helping to keep out those negative thoughts of doubt which would plant tares among our wheat, and therefore, instead of anything of effort, such contemplation should be accompanied by a feeling of pleasure and restfulness in foreseeing the certain accomplishment of our desires. This is that making our requests known to God _with thanksgiving_ which St. Paul recommends, and it has its