What is the importance of confidentiality in the relationship between a solicitor and client?

At page 1244 of MacDonald Estate v. Martin, supra, addressing the solicitor/client relationship, the court held that: Nothing is more important to the preservation of this relationship than the confidentiality of information passing between a solicitor and his or her client. The legal profession has distinguished itself from other professions by the sanctity with which these communications are treated. ... This tradition assumes particular importance when a client bares his or her soul in civil or criminal litigation. Clients do this in the justifiable belief that nothing they say will be used against them and to the advantage of the adversary. Loss of this confidence would deliver a serious blow to the integrity of the profession and to the public’s confidence in the administration of justice. ... In preparing for the hearing of a contentious matter, a client will often be required to reveal to the lawyer retained highly confidential information. The client’s most secret devices and desires, the client’s most frightening fears will often, of necessity, be revealed. The client must be secure in the knowledge that the lawyer will neither disclose nor take advantage of these revelations.