"In beginning this practice of meditation it is desirable to watch closely its physical effects. Methods prescribed by those who understand the matter ought never to cause headache or any other pain, yet such results do sometimes occur in particular cases. It is true that meditation strains the thought and attention a little further than its customary point in any individual, but that should be so carefully done, so free from any kind of excess, as not to cause any physical ill-effects. Sometimes a person takes it up too strenuously and for too long at a time, or when the body is not in a fit state of health, and the consequence is a certain amount of suffering. It is fatally easy to press one’s physical brain just a little too far, and when that happens it is often difficult to recover equilibrium. Sometimes a condition may be produced in a few days which it will take years to set right; so anyone who begins to feel any unpleasant effects should at once stop the practice for a while and attend to his physical health, and if possible consult someone who knows more than he does about the subject."