It is clear that one does not start with the alleged infringement, read the patent, and ask whether the patentee meant to cover it. But it is sometimes necessary to have regard to the infringement in order to identify the question which has to be asked on construction. In Technip France's Patent  RPC 46 Jacob LJ put it in this way:
"Although it has often been said that the question of construction does not depend on the alleged infringement ("as if we had to construe it before the defendant was born") per Lord Esher M.R. in Nobel's Explosives Co. v Anderson (1894) 11 R.P.C. 519 at 523), questions of construction seldom arise in the abstract. That is why most sensible discussions of the meaning of language run on the general lines "does it mean this, or that, or the other?" Rather than the open-ended "what does it mean?"I wonder whether I can encourage people to adopt the title "Man of the World Rule" for this principle - after the bleak but beautiful song by Peter Green?