Since Malcolm, the issue of knowledge of a disability has gained a great deal of importance because it is a requirement for a successful claim for a failure to make reasonable adjustments, which is now the most important head of claim. It has also become a requirement for disability-related discrimination in the unlikely event that the comparator problem is overcome. Although there is no statutory test in the latter case, the principles are likely to be similar to those that arise in the statutory test for knowledge in a reasonable adjustments case and so clarification of these principles is of considerable importance.

Clarification has not been achieved by the case of Department of Work and Pensions v Alam, in which the Scottish Employment Appeal Tribunal states that an employer is able to make out this defence if it is ignorant of either the disability or its effects and, therefore, it must be aware of both for a claim to succeed. This is contrary to the earlier authority of Eastern and Coastal Kent PCT v Grey, which said that ignorance of both is required for the defence, although this was admittedly not very helpful, being notable as the only Employment Appeal Tribunal judgment in the last year to be internally inconsistent. The decision by Justice Silber to remit the case when it was apparently quite unnecessary to do so was interpreted by Lady Smith as showing that it did not really mean what it appeared to say on its face.

However, the real problem with both of these judgments is that they are trying to carry out statutory interpretation in a vacuum. It is difficult to properly get a grip on the meaning of a word like ’and’ in a complex piece of legislation without trying to understand what is being said from a broader perspective and there are many issues which are completely ignored but which could be of considerable assistance. For example, the relevant section also includes the word ‘disability’ and, as I discussed in this post, this can mean both the underlying medical condition and the impairment caused by it. As this has the result of making the ‘disability’ and its effects equivalent for all purposes, neutralising the use of the word ‘and’, this suggests that Grey is correct, although for reasons different from those given in the decision.

On the other hand, I am sympathetic to the result of the Alam case, and of Ridout v T C Group, which it cites. This is another reason why I think that the word ’disability’ should refer only to the effects of the impairment and not at all to the diagnostic label. If so, there would be a defence if an employer knew about a medical condition but not its effects but no defence if, for example, it knew that an employee used a wheelchair without knowing the reason why. This approach is also consistent with the logic of constructive knowledge. A person who knows the effects of a disability knows everything necessary in order to make reasonable adjustments but a person who knows only the label does not. This issue must be urgently considered by a higher court to ensure the coherence of disability discrimination law.