(b) From ‘but-for’ to ‘but-why’
Lord Browne-Wilkinson (dissenting), Nagarajan v LRT  1 AC 501 (HL) at 510:
‘[Courts should not introduce] … something akin to strict liability … which will lead to individuals being stamped as racially discriminatory … where these matters were not consciously in their minds.’
Per Lord Woolf, MR, Khan v Chief Constable of West Yorkshire,  ICR 1169, (CA) .
‘To regard a person as acting unlawfully when he had not been motivated either consciously or unconsciously by any discriminatory motive is hardly likely to assist the objective of promoting harmonious racial relations.’
Shamoon v Chief Constable of the RUC  ICR 337 (HL). In Nagarajan v LRT
 1 AC 501, at 511, Lord Nicholls suggested: ‘Save in obvious cases, answering the crucial question will call for some consideration of the mental processes of the alleged discriminator.’
(c) The Current Approach – Three Classes
JFS identified 2 cases.4Amnesty v Ahmed identified a third ()
(a) ‘Obvious’ or overt discrimination – Motive not relevant – no further inquiry required
(b) ‘Less Obvious’ (See Lord Nicholls’ view in Nagarajan above).
(c) ‘Background cases’
Seide v Gillette Industries  IRLR 427 (EAT).
(3) Where the Victim Does Not Belong to the Protected Group
The definition contains no possessive adjective. The treatment must be ‘because of a protected characteristic’ and not ‘because of his protected characteristic’. This does not apply to work cases where the characteristic is marriage or civil partnership: s.13(4).
4 - (Lord Phillips), - (Lady Hale),  (Lord Mance), - (Lord Kerr),  (Lord Clarke).