"The difficulty, if not danger, thus created of attempting to state the conditions which must be fulfilled before a given kind of conduct or of unfairness amounts to an invalidating cause is greatly increased by the introduction of the consideration that the equity must be such as ought to prevail against the claims of the creditor as a possibly innocent third party. But it is clearly necessary to distinguish between, on the one hand, cases in which a wife, alive to the nature and effect of the obligation she is undertaking, is procured to become her husband's surety by the exertion by him upon her of undue influence, affirmatively established, and on the other hand, cases where she does not understand the effect of the document or the nature of the transaction of suretyship. ... [I omit the passages dealing with undue influence.] In the second case, that where the wife agrees to become surety at the instance of her husband though she does not understand the effect of the document or the nature of the transaction, her failure to do so may be the result of the husband's actually misleading her, but in any case it could hardly occur without some impropriety on his part even if that impropriety consisted only in his neglect to inform her of the exact nature of that to which she is willing blindly, ignorantly or mistakenly to assent. But, where the substantial or only ground for impeaching the instrument is misunderstanding or want of understanding of its contents or effect, the amount of reliance placed by the creditor upon the husband for the purpose of informing his wife of what she was about must be of great importance. If the creditor takes adequate steps to inform her and reasonably supposes that she has an adequate comprehension of the obligations she is undertaking and an understanding of the effect of the transaction, the fact that she has failed to grasp some material part of the document, or, indeed, the significance of what she is doing, cannot, I think, in itself give her an equity to set it aside, notwithstanding that at an earlier stage the creditor relied upon her husband to obtain her consent to enter into the obligation of surety. The creditor relied upon her husband to obtain her consent to enter into the obligation of surety. The creditor may have done enough by superintending himself the execution of the document and by attempting to assure himself by means of questions or explanation that she knows to what she is committing herself. The sufficiency of this must depend on circumstances, as, for example, the ramifications and complexities of the transaction, the amount of deception practised by the husband upon his wife and the intelligence and business understanding of the woman. But, if the wife has been in receipt of the advice of a stranger whom the creditor believes on reasonable ground to be competent, independent and disinterested, then the circumstances would need to be very exceptional before the creditor could be held bound by any equity which otherwise might arise from the husband's conduct and his wife's actual failure to understand the transaction: Cf. per Cussen J. 97 (1925) V.L.R., at p. 649. If undue influence in the full sense is not made out but the elements of pressure, surprise, misrepresentation or some or one of them combine with or cause a misunderstanding or failure to understand the document or transaction, the final question must be whether the grounds upon which the creditor believed that the document was fairly obtained and executed by a woman sufficiently understanding its purport and effect were such that it would be inequitable to fix the creditor with the consequences of the husband's improper or unfair dealing with his wife. Apart from the unwisdom or improvidence of the transaction into which he persuaded her, the facts of the present case do not show that Estyn Jones exercised any influence over his wife which could be considered undue or a ground for interference by a court of equity. His enthusiasm for a project or enterprise that it was foolish to embark upon was not shared by his wife, but it is impossible to believe that she did not understand as well as he that, if the purchase was to be made, whatever money was needed must be found by her... But it was not a case where a husband having incurred a heavy indebtedness is relied upon by a creditor to obtain from his wife a guarantee which will improve the position of the creditor to the detriment of the wife, who will obtain no benefit except the satisfaction of relieving her husband for a time from one of his embarrassments." (See too: Garcia at 18, 21, 25, 31 and 33).