Analyse the strengths and weaknesses of the ‘but for’ test for factual causation.

Begin by setting out what the ‘but for’ test is and how it works: i.e. ‘but for D’s action, would C’s loss still have occurred?'. If the answer is yes then this may enable D’s action to be eliminated from the list of possible causes. If the answer is no, then D’s action remains in the list of possible causes of C’s loss. You should give an example of the test in operation: Barnett v Chelsea or McWilliams v Sir William Arrol & Co. The test has been described as a ‘simple filter’ and operates as an effective first step in many cases.

However, there are a number of situations in which it is ineffective, or gives an irrational result. An example of the latter occurs where there is more than one tortious cause (multiple causes): matches in the gas-filled room. It must be ‘over-ruled’ with joint liability; similarly, cumulative causes as in Fitzgerald v Lane. It will be ineffective when it cannot be answered: ‘indeterminate causes’ as in Cook v Lewis. Further, consecutive causes: describe the issues in Performance Cars v Abraham, Baker v Willoughby, and Jobling v Associated Dairies. You may conclude that there are so many exceptions that the ‘but for’ test is redundant.