What is the current state of the law on pain and suffering?

The majority opinion written by Lamer J.A. (as he then was) adopted the following passage from the reasons of Hawkins J. in Ford v. Wiley (1889), 23 Q.B.D. 203 at p. 220: The legality of a painful operation must be governed by the necessity for it, and even where a desirable and legitimate object is sought to be attained, the magnitude of the operation and the pain caused thereby must not so far outbalance the importance of the end as to make it clear to any reasonable person that it is preferable the object should be abandoned rather than that disproportionate suffering should be inflicted.