In theory, recourse to the grievance arbitration would appear to be an efficient means of controlling the abuse of powers (i.e. violations of the collective agreement) by the employer. Indeed, experience has borne out the truth of this affirmation. Mainly due to the management rights principle however, there still remain several important lacunae in this regard. On the one hand, by invoking the so-called management rights principle as a favorite means for circumscribing the arbitrator's jurisdiction, the Supreme Court of Canada has greatly diminished the efficacy of the arbitration process. This has occured primarily through the quashing of arbitration decisions either on the basis of error of law or else by limiting the arbitrator's discretion in disciplinary cases. On the other hand, it would be just as harmful to the efficiency of the arbitration process if arbitrators themselves were to abuse the management rights principle in interpreting and applying collective agreements. In general, arbitrators have proved to be highly conscious of this problem. By the same token, arbitrators have been faced with the problem of whether or not to discipline acts of insubordination even though employees may have been provoked by an abuse of authority on the part of the employer. All in all, arbitrators, by their attitude, appear to manifest a desire of ensuring the efficient functioning of the arbitration process, without acting to the detriment of management rights. In this regard, the Supreme Court of Canada, with the notable exception of Chief Justice Laskin, would seem to be fighting a rear-guard action by continually emphasizing management rights.