It is not easy to define terms precisely and then get everyone to agree to the definition (no matter what one's theoretical orientation is) and it certainly would be a good thing if there were more of a consensus on how important terms are defined. However, I think CT is fairly clear about what we mean when we talk about "Socratic questioning" or "guided discovery."

In Cognitive Therapy of Depression (1979, pp.69-71) Beck and company say:

"Use Questioning Rather Than Disputation and Indocrination

A well-timed, carefully phrased series of questions can help the patient to isolate and carefully consider a specific issue, decision, or notion. A series of questions may open the patient's thinking around a specific issue, and thereby allow him to consider other information and experiences - either recent or past. The patient's curiosity can be raised by a series of questions. His apparently rigidly stated views become tentative hypotheses. In this way, questions are used to relieve depressed, constricted thinking.
-snip-
Questions constitute an important and powerful tool for identifying, considering, and correcting cognitions and beliefs. As with other powerful tools, they can be misused or artlessly applied. The patient may feel he is being cross-examined or that he is being attacked if questions are used to 'trap' him into contradicting himself. In addition, open-ended questioning sometimes leaves the patient in the defensive position of trying to guess what the therapist 'expects' for an answer. Questions must be carefully timed and phrased so as to help the patient recognize and consider his notions reflectively - to weigh his thoughts with objectivity." (They also give three good examples of how we use questioning on pages 68-70.)

A more contemporary discussion of how we use questioning can be found in the summary of the princilpes of CT that Dr. Beck and I included in our chapter for the second edition of Major Theories of Personality Disorder (Lenzenweger & Clarkin, 2004):

"The approach used in Cognitive Therapy has been described as "collaborative empiricism" (Beck, et al., 1979, Chap. 3). The therapist endeavors to work with the client to help him or her to recognize the factors that contribute to problems, to test the validity of the thoughts, beliefs, and assumptions which prove important, and to make the necessary changes in cognition and behavior. While it is clear that very different therapeutic approaches ranging from philosophical debate to operant conditioning can be effective with at least some clients, collaborative empiricism has substantial advantages. By actively collaborating with the client, the therapist minimizes the resistance and oppositionality which is often elicited by taking an authoritarian role, yet the therapist is still in a position to structure each session as well as the overall course of therapy so as to be as efficient and effective as possible (Beck, et al., 1979, Chap. 4).

One part of this collaborative approach is an emphasis on a process of "guided discovery." If the therapist guides the client by asking questions, making observations, and asking the client to monitor relevant aspects of the situation, the therapist can help the client develop an understanding of his or her problems, explore possible solutions, develop plans for dealing with the problems, and implement the plans quite effectively. Guided discovery has an advantage over approaches in which the therapist unilaterally develops an understanding of the problems and proposes solutions in that it maximizes client involvement in therapy sessions and minimizes the possibility of the client's feeling that the therapist' ideas are being imposed on the client. In addition, since the client is actively involved in the process of developing an understanding of the problems and coming up with a solution, the client also has an opportunity to learn an effective approach to dealing with problems and should be better able to deal with future problems when they arise."

Beck, A. T., Rush, A. J., Shaw, B. F., & Emery, G. (1979). Cognitive therapy of depression. New York: Guilford Press.

Pretzer, J. L. & Beck, A. T. (2004). A cognitive theory of personality disorders. In: M. Lenzenweger & J. Clarkin (Eds.) Major theories of personality disorder (2nd Edition). New York: Guilford Press.