A priori it seems clear that without self-control exercised by the individuals participating in conversation, conversation is impossible. In general, conversations do not occur among the inmates of Bedlam, or other houses of the insane. Thus,
(P5) Principle of self-control.
For higher conversation, where spiritual enlightenment and initiation are being sought, it seems equally clear that self-control will entail some positive aspect, and not merely the negative one of self-restraint. In anthroposophical conversation, the individual will want to contribute contents that disclose his (her) understanding of the spiritual world, and will want to do this in a manner that everyone else present can accept and to which they can respond. Self-control in Goethean conversation is self-control on behalf of others.
The maxim or injunction of the anthroposophist in conversation is thus "Be a work of art." Self-expression in anthroposophical company is never a gesture of self-indulgence, of private commentary, of undisciplined rambling or any expression of subjective inclination applied to a particular moment. It is always a gesture on behalf of that which is objective and universal in the moment. Conversational control is maintaining the contents and the attitudes of conversation as something that everyone present can always respond to objectively.

Loose talk
As a visitor to several Bedlams I find this post both disrespectful and discriminatory Carl. Your information that conversations do not take place among such groups is factually incorrect.
These people are human beings in whom slumber all the faculties you wish to entertain in your dream catcher of principles.
Will you be suggesting that a rationality test should hold back the poor fools at the door who might disrupt our cosy conversation? I sincerely hope not.
Speech is not compulsory for participation in the kind of conversation I am seeking. Self control in listening - not only self-restraint - is practiced by many imaginative folk that you might consider to be insane.
Carl
I think this is an exceptional post - especially the self-control on the behalf of others.
Thanks again for your insight.
Caryn
The Thinking Exercise
The thinking exercise is terrifically important and it needs to be practiced by all true anthroposophists. Here's how I think it works.
The mind wants to establish relatedness with all its objects, and is prone to wander freely if unchecked. Such wandering is spiritually non-productive. It's the best way we have to waste time, both our own and others'. The thinking exercise is a technique to check the free associations of feeling, and to strengthen the spiritual faculties of self-control and pure thinking.
Not all predicates fit an object, and only a few fit it well. This can be understood clearly if the object is a simple one, like a pin. Here one needs to work to find predicates that are appropriate for the object, for example "straight," "tapered," "zinc-plated," "used to bind cloth together," and so forth. Allowing the mind to entertain unrelated predicates leads one very quickly and very observably into dream life.
The thinking exercise is an exercise of correct predication.
Correct predication is also practiced in Goethean conversation. Under these conditions, the objects are more complicated than pins, but the principle is the same. One tries to find the right predicate and tries to express it in the right way. The others present judge one's correctness and self-possession by subtle and overt signs. That social judgment, if it is sensitive and skillful, induces an etheric field that levitates the conversational participants.
The spiritual nature in thinking is thus brought out during conversation in exactly the same way it is in the pin exercise.