A lock with a locking mechanism comprises a rotary catch, a pawl for engaging the rotary catch, a blocking lever capable of blocking the pawl if the latter is located in its catching position, and a releasing lever for opening or releasing the locking mechanism. When the releasing lever is actuated, the pawl and, if applicable, the blocking lever is moved out of its blocking position provided that the releasing lever is moved in a usual manner and the releasing lever is not exposed to increased or excessive accelerations. In case of an increased or excessive acceleration of the releasing lever such as caused by a crash or impact, an arresting device prevents the releasing lever from disengaging the pawl and optionally the blocking lever of the pawl. The arresting device is further releasable with the return of the releasing lever to the initial rest position.