Permissiveness is one of the basic therapeutic attitudes in mental hospital treatment and administration. It is essential especially for the sickest patients, who need the experience of truly permissive relationships in order to feel some degree of safety in allowing contact with other human beings. The regressed, hyperactive, or destructive patient may be permitted very little latitude of activity in order to protect him, others, and property, but a basically permissive attitude will help the patient in feeling that he is respected as a sick adult and that we would like to give him more freedom of activity if we could within the limitations of his illness. There are many criticisms of permissiveness which most often result from misunderstanding; that is, the errors in therapy are not due to permissiveness but to contaminants of the permissive attitude. This paper lists the 4 major contaminants: sanction, seduction, submissiveness, and indifference. No doubt there are many others. Perhaps the considerations above will stimulate some thought on this important and controversial subject and more complete analyses will result.Abstract Teaser