A writer has also called the attention of young mediums to another undesirable class of psychic hangers-on at seances, as follows: "There are some people who, when they sit in a circle, are extremely helpful, and give off the right kind of force that readily blends with that of the sensitive; but there are others who draw upon and appropriate the psychic forces which are needed by the medium, or by the spirits through the medium. While they mean well, enjoy the seances, and feel 'SO much better' after them, the success of the circle is endangered so far as the object for which it was formed is concerned. Such persons are 'psychic sponges,' and should be requested to sit outside the circle, or be asked kindly to refrain from attending." Investigate Your Spirits. Finally, the young medium should understand the true nature of the spirits, and just how far he may be safely guided by their advice and wishes. The instructions given by an intelligent spirit of good character may be safely followed as a rule, but the character and general intelligence of a particular spirit must first be ascertained through acquaintance with him. Until the character of a spirit has been fully established, and his claim to intelligence well supported by his messages, the medium will do well to rely on his or her own good judgment and intuition. As a writer has well said: "The medium must keep a level head and proceed cautiously. He should never allow any spirit, in or out of the body, to usurp his right of private judgment or exercise any undue authority over him. Eternal vigilance is the price of liberty; you must use your own discretion and try the spirits before you trust to them." Spirits Are Still Human Beings.