Utility of the NESS Test of Factual Causation in Scots Law

It is well accepted in Scots law that, in order for a delictual claim to be successful, the pursuer must establish factual causation. In most cases, he or she will have to satisfy the ‘but for’ test, however because this can lead to harsh results the courts have sometimes adopted a more relaxed approach to causation. Thus, there are various exceptions to the general rule (namely the 'but for’ test) including the ‘material contribution’ test adopted in Wardlaw v Bonnington Castings Ltd. This article seeks to challenge the current Scots law approach to causation and to consider the merits of replacing the ‘but for’ test, along with the various exceptions thereto, with a single test of factual causation known as the NESS test. It will be contended that there are three main
‘criteria’ against which the utility of a causation test can be gauged and, with close reference to these ‘criteria’, it will be argued that the current Scots law approach to factual causation is inadequate. This article concludes that NESS satisfies all three ‘criteria’ and hence constitutes a promising alternative to the current law; one that the Scottish courts would do well to consider.