In order always to be in a state of perfect health two things are necessary.  Deny the power of disease over yourself.  In the unyielding will is health.  In the weak, vacillating, fearful mind is disease and death.  At the same time always be in perfect magnetic trim with the physical laws of health.  A knowledge of the latter and the ascension of a fearless mental attitude will open up hitherto unrecognised channels of physical and mental expression.  Physiological researches have led sincere investigators to the inevitable conclusion that there is subtle, refined, dynamic substance, a reality that binds up the reorganization, causes growth, vitality and motion; repairs injuries; makes up losses; overcomes and cures diseases.  Von Helment called it “Archeus”; Stahl called it “Anima;” Whytt called it the “sentiment principle;” Dr. Cullen called it “Caloric;” Dr. Darwin called it “Sensorial energy”; Rush called it “Occult cause;” and many other names such as “Vital Principle,” “Living power,” “Conservative Power,” “Odic Force,” etc., etc., have been given to it.  We of India have recognised it and devised Yoga methods for controlling it; we call it Prana and only in India do you come across men who possess pranic control or control over universal energy.

There exists in your physical organism reserve stores of vital energy stored away for your use, particularly in that central ganglion of your vital battery known as the Solar Plexus and generally in the chain of ganglia or storage batteries along and up your spine and elsewhere in other nerve-centres.  The solar plexus is also known as the Abdominal Brain and your brain depends and draws upon this vital centre for its energies.  You will find after the prolonged concentration and brain-work that this part of your body—­at the back of pit of stomach—­becomes warm.  Now when you engage in physical exercise, for instance, you must have noticed how at first you soon get tired and all done up.  But if you wait a little and then start again, you will find how the sense of fatigue has quite passed away and you can run your body under full pressure for a very long time, and the more you exert yourself the greater and more powerful the surging up of your vital energy.  With each new exertion you seem to acquire a fresh start.  This has puzzled physiologists.  You will find a parallel phenomenon in mental work.  You may experience a sense of weariness and fatigue in some brain-work which demands close thinking and attention, but if you attack your work a little later after the first effort you will do your work a surprising degree of freshness, vigour, and enthusiasm far surpassing the original attempt.  Again everyone can and does put forth universal energy under pressure of some urgent necessity, which will startle even himself.  No matter who you are and what your physical condition, there is an enormous amount of power in your body that has never been drawn upon at all and impatiently