30 While characterised as one of misconduct by silence, the complaint is, in substance, a complaint of misconduct by half-truth. The half-truth concept is illustrated by the decision of the United States Court of Appeals in P Lorrilard Co v Federal Trade Commission 186 F 2d 52 (1950), a tobacco advertising case in which a cigarette manufacturer had claimed that its "Old Gold" product would not harm the throat, quoting a Reader's Digest article comparing various brands of cigarette. The court said:
"The fault with this advertising was not that it did not print all that the Reader's Digest article said, but that it printed a small part thereof in such a way as to create an entirely false and misleading impression, not only as to what was said in the article, but also as to the quality of the company's cigarettes. Almost anyone reading the advertisements or listening to the radio broadcasts would have gained the very definite impression that Old Gold cigarettes were less irritating to the throat and less harmful than other leading brands of cigarettes because they contained substantially less nicotine, tars and resins, and that the Reader's Digest had established this fact in impartial laboratory tests; and few would have troubled to look up the Reader's Digest to see what it really had said. The truth was exactly the opposite. There was no substantial difference in Old Gold cigarettes and the other leading brands with respect to their content of nicotine, tars and resins and this was what the Reader's Digest article plainly said."
31 The same thinking caused the Full Federal Court to observe in Fraser v NRMA Holdings Ltd (1995) 55 FCR 452 that, where information is provided, it must constitute a "full and fair disclosure of all relevant facts." In other words, it is not enough that what is said, considered in isolation, is literally true if there is another part of the overall story that should be disclosed and, if disclosed, would cause the total message to be different.
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34 In a situation of arm's length commercial negotiations, however, there is no generally prevailing legal requirement that one party not take advantage of superior knowledge; much less is there a requirement to surrender the advantages that superior knowledge entail. In Lam v Ausintel Investments Australia Pty Ltd (1989) 97 FLR 458, Gleeson CJ said at 475:
"Where parties are dealing at arms' length in a commercial situation in which they have conflicting interests it will often be the case that one party will be aware of information which, if known to the other, would or might cause that other party to take a different negotiating stance. This does not in itself impose any obligation on the first party to bring the information to the attention of the other party, and failure to do so would not, without more, ordinarily be regarded as dishonesty or even sharp practice."
35 Case law about s 52 of the Trade Practices Act 1974 (Cth) and its State equivalents such as s 42 of the Fair Trading Act makes it clear that the factor that may give rise to a requirement to break silence - in the sense that failure to do so will be misleading or deceptive - will be found in the whole of the circumstances in which silence is maintained. The most often quoted statement of the relevant principles is probably that of the Full Federal Court in Demagogue Pty Ltd v Ramensky (1992) 39 FCR 31. The matter was summarised thus by Handley JA (with whom Hodgson JA and Gzell J agreed) in Metalcorp Recyclers Pty Ltd v Metal Manufactures Ltd [2003] NSWCA 213; (2004) Aust Contract R 90-186:
"A finding of misleading or deceptive conduct is open where that conduct, by word or deed, conveyed a misrepresentation ( Wardley Australia Ltd v Western Australia (1992) 175 CLR 514). In this case the misrepresentation is said to have been conveyed by silence, but that is an inadequate and incomplete description. The relevant principles were felicitously summarised by Black CJ in Demagogue Pty Limited v Ramensky (1992) 39 FCR 31 , 32:
'Silence is to be assessed as a circumstance like any other. To say this is certainly not to impose any general duty of disclosure; the question is simply whether, having regard to all the relevant circumstances, there has been conduct that is misleading or deceptive … to speak of "mere silence" or a duty of disclosure can divert attention from that primary question. Although "mere silence" is a convenient way of describing some fact situations, there is in truth no such thing as "mere silence" because the significance of silence always falls to be considered in the context in which it occurs. That context may or may not include facts giving rise to a reasonable expectation, in the circumstances of the case, that if particular matters exist they will be disclosed.'