In order for one to gain knowledge, it is necessary to use to the best advantage the mental instruments and tools that he finds at his disposal. And again, one must develop and improve such tools--put a keen edge upon them, etc. Not only does one gain a great benefit from a development of the faculties of perception, but he also acquires an additional benefit from the training of the whole mind arising from the mental discipline and training resulting from the former exercises, etc. In our previous lessons we have pointed out some of the means by which these faculties might be greatly improved, and their efficiency increased. In this lesson we shall point out certain directions in which the Perceptive faculties may be trained. We trust that the simplicity of the idea may not cause any of our students to lose interest in the work. If they only knew just what such development would lead to they would gladly follow our suggestions in the matter. Every one of the ideas and exercises given by us are intended to lead up to the strengthening of the Mind, and the attainment of powers and the unfoldment of faculties. There is no royal road to Raja Yoga, but the student will be well repaid for the work of climbing the hill of Attainment. In view of the above, let us examine the question of The Senses. Through the doors of the senses Man receives all his information regarding the outside world. If he keeps these doors but half open, or crowded up with obstacles and rubbish, he may expect to receive but few messages from outside. But if he keeps his doorways clear, and clean, he will obtain the best that is passing his way. If one were born without sense-organs--no matter how good a Mind he might have--he would be compelled to live his life in a dreamy plant-life stage of existence, with little or no consciousness. The Mind would be like a seed in the earth, that for some reason was prevented from growing. One may object that the highest ideas do not come to us through the senses, but the reply is that the things obtained through the senses are the "raw material" upon which the mind works, and fashions the beautiful things that it is able to produce in its highest stages. Just as is the body dependent for growth upon the nourishment taken into it, so is the mind dependent for growth upon the impressions received from the Universe--and these impressions come largely through the senses. It may be objected to that we know many things that we have not received through our senses. But, does the objector include the impressions that came through his senses in some previous existence, and which have been impressed upon his instinctive mind, or soul-memory? It is true that there are higher senses than those usually recognized, but Nature insists upon one learning the lessons of the lower grades before attempting those of the higher.