As all disciples have to be focused on the mental plane and must operate from that level of consciousness, the understanding of this type of consciousness is one of major importance. It is glibly and most easily said that disciples and (necessarily so) initiates must use the mind, and that their polarization must be mental. But what does this mean? Let me give you some concise definitions of this ray energy, leaving you to make your own individual application, and from your study of these concepts anent the mind, learn to gauge your own mental condition. [590]

1. The energy of what is so peculiarly called "concrete science" is the quality or the conditioning nature of the fifth ray.
2. It is pre-eminently the substance of the mental plane. This plane corresponds to the third subplane of the physical plane, and is therefore gaseous in nature - if you care to use its correspondence as a symbol of its nature. It is volatile, easily dispersed, is the receptive agent of illumination, and can be poisonous in its effect, for there are undoubtedly conditions in which "the mind is the slayer of the Real."
3. This energy is characterized by three qualities:
   1. The quality which is the result of relationship with the Spiritual Triad. We call this "abstract mind" and the impact which affects it comes from the atmic level of the Spiritual Triad, that of spiritual will.
   2. The quality which in this solar system is easily responsive to the major ray of the planet, that of love-wisdom. So responsive is it that - in conjunction with emanations from the three worlds - it has produced the one existent form upon the mental plane. This form (in the planetary sense) is that of the Kingdom of God and, in the individual sense, is that of the ego or soul.
   3. The quality which is basically related to the emanations or vibrations arising from the three worlds; these creatively result in the myriads of thought-forms which are found upon the lower levels of the mental plane. It might therefore be said that these qualities or aspects of the fifth ray of spiritual energy produce:
                     Pure thought
                     The thinker or the Son of Mind
                     Thought-forms
4. This energy (as far as mankind is concerned) is the thought-form making energy, and all impressions from the physical, etheric and astral planes force it into activity on the level of concrete knowledge, with a resultant kaleidoscopic presentation of thought-forms. [591]
5. It is fundamentally the most potent energy at this time in the planet, because it was brought to maturity in the first solar system, that of active intelligence.
6. It is the energy which admits humanity (and particularly the trained disciple or initiate) into the mysteries of the Mind of God Himself. It is the "substantial" key to the Universal Mind.
7. It is profoundly susceptible to the energy of Love-Wisdom, and its fusion with the love aspect is given the name of "wisdom" by us, because all wisdom is knowledge gained by experience and implemented by love.
8. This energy, in its three aspects, is related in a peculiar sense to the three Buddhas of Activity. These great Lives reached Their present state of development in the previous solar system.
9. This energy, in so far as it is considered as the mental energy of a human being - and this is one of its minor limitations though a major one for a human being - is the higher correspondence of the physical brain. It might be said that the brain exists because the mind exists and needs a brain as its focal point upon the physical plane.
10. The quality of this energy of concrete knowledge or science is twofold:
    1. It is extraordinarily responsive to impressions coming from some source or other.
    2. It is rapidly thrown into forms in response to impression.
11. The impressions received come from three sources and are sequentially revealed to man. These three are:
    1. Impressions from the three worlds; these come, first of all, from the individual and then, secondly, from the levels of planetary consciousness.
    2. Impressions from the soul, the Son of Mind, upon the level of mentality itself.
    3. Impressions from the Spiritual Triad, via the antahkarana; these come when the antahkarana is constructed or in process of construction. [592]
12. This energy is essentially a light-bearer. It responds - again sequentially in time and space - to the light of the Logos. It is for this reason that the mind is regarded both as illumined when higher contacts are present and as an illuminator where the lower planes are concerned.
13. This energy is (from the human standpoint) awakened and brought into activity through the action of the five senses which are the conveyors of information from the three worlds to the mental plane. It might be said that
    1. Five streams of informative energy, therefore, make their impact upon the concrete mind and emanate from the physic-astral plane.
    2. Three streams of energy, coming from the soul, also make an impression upon the concrete mind.
    3. One stream of energy - during the initiatory process - contacts the mind. This comes from the Spiritual Triad and utilizes the antahkarana.
14. The energy of this fifth ray might be regarded as the common sense, because it receives all these impacts of varying energies, synthesizes them, produces order out of the many ceaseless impacts and interprets them, thus creating the multiplicity of forms to which we give the name of "world thought."
15. This energy transforms the divine ideas into human ideals, relating the knowledges, and sciences of humanity to these ideals, thus making them workable factors in human evolution, its cultures and civilizations.