struggled with this issue in a case concerning a letter from a bank, not intended by it to have any binding effect, but which gave the appearance of a guarantee­.254 The court decided to impute an intention to make a declaration of intent, albeit not one of the character which the objective terms it used conveyed (thus the matter was for determination under §119).

Though motive is generally irrelevant in the rules on error, it is relevant to cases of deceit (or unlawful duress) under §123: a person who has been induced to make a declaration of intent as a result of such deceit is given an absolute right to avoid the declaration, and there is no requirement that the party deceived be labouring under an error as to the contents of the declaration. Deceit means, however, wilful or intentional misrepresentation, and does not cover a careless or innocent misrepresentation. There is thus, from a Common law or mixed legal perspective, a gap in the provisions of the BGB. In practice, however, culpa in contrahendo (discussed earlier) is used to tackle some such cases, namely those where a party has negligently persuaded another to enter into a contract. That still leaves the innocent misrepresentation largely irremediable, however. Cases of extortion will be discussed in the next section.

Overall, the German approach, though not solving all difficulties in the field, by adopting a simple, single division in the category of relevant and irrelevant error, results in a taxonomy whose two categories are determined by criteria of the same type and one which is able to implement relatively easily the preferred policy of what may be called ‘selective subjectivism’, that being a preference for the subjective will over objective declaration so long as the disparity between the two is manifested in a matter which forms part of the declaration of the party in error. The German approach is not without its flaws, the inclusion of the substantial error provision of §119(2) commonly being thought of us such a flaw, but the analysis it provides is at least clearer than that offered under both the English and Scottish approaches.

(v)  An ideal approach to promissory error?

Is there an ideal approach to dealing with errors affecting promises? To pose such a question assumes that one knows what is meant by a promise and one might imagine that, a definition of promise having been adopted in Chapter 1 of this work, such an assumption would be justified. But what that definition necessarily obscures is the detail of the debates about what it means to have promised something which are the very essence of

254  BGHZ 91, 324.

the doctrine of error. What therefore is required, before a legal system can construct a rational and desirable approach to dealing with error, is for it to adopt a general approach to determining what will be considered to have been constituted by a promise. This means considering whether what a party should be taken to have promised should be what it reasonably appears to have promised, what it subjectively thought it was promising, what it would subjectively have promised had it been appraised of the correct facts, some mixture of these approaches for different circumstances, or some entirely different approach altogether.

It is suggested that a sensible and principled approach might be as follows:

(1)that promises be judged objectively – this may be called the ‘general approach to assessing the content of voluntary obligations’ – but

(2)a deviation from this approach in favour of actual subjective intention should be permitted when such subjective intention does not align with the manifestation of that intention given in terms of the declaration of consent – this may be called the ‘general policy concerning error’. Matters on which a party thus remains silent, or which were not expressed as part of what it was agreeing to, or which merely form the background reasons for it contracting (save in cases of induced error), will thus not properly be able to form the subject of a relevant plea of error.

Such an approach is essentially the Germanic approach to error, and it is one which is beginning to find favour in non-Germanic systems.255 It is consistent with a high regard for the value of promises as acts of will, in so far as such acts of will are generally judged by the objective manifestation of such acts of will, but it reverts to underlying subjective expressions of will in order to deal with circumstances in which it is judged that it would be unjust to ignore a discrepancy between the objective appearance of consent and the underlying subjective will of parties. Approached in such a fashion, the field of error need not be viewed as exposing alleged weakness of a will approach to contractual liability; rather, the issues posed by error problems simply reflect a deeper and ever present tension in the law as to whether juristic consequences should follow from manifested behaviour or from underlying psychological consent (however that is judged). That difficult question is one which affects all theories of contract law, and not just will or promissory theories.

255  It has, for instance, been proposed as a workable taxonomy in Scotland: see n. 231 above.