Analysis of various forms of knowledge was made by Peter Gibson J in Baden v Societe Generale pour Favoriser le Duveloppement du Commerce et de l'Industrie en France SA (1982)  4 All ER 161:
Knowledge may be proved affirmatively or inferred from circumstances. The various mental states which may be involved were analysed by Peter Gibson J in Baden’s case  4 All ER 161 at 235 as comprising: "(i) actual knowledge; (ii) wilfully shutting one’s eyes to the obvious; (iii) wilfully and recklessly failing to make such inquiries as an honest and reasonable man would make; (iv) knowledge of circumstances which would indicate the facts to an honest and reasonable man; (v) knowledge of circumstances which would put an honest and reasonable man on inquiry." According to Peter Gibson J, a person in category (ii) or (iii) will be taken to have actual knowledge, while a person in categories (iv) or (v) has constructive notice only. I gratefully adopt the classification but would warn against over refinement or a too ready assumption that categories (iv) or (v) are necessarily cases of constructive notice only. The true distinction is between honesty and dishonesty. It is essentially a jury question. If a man does not draw the obvious inferences or make the obvious inquiries, the question is: why not? If it is because, however foolishly, he did not suspect wrongdoing or, having suspected it, had his suspicions allayed, however unreasonably, that is one thing. But if he did suspect wrongdoing yet failed to make inquiries because "he did not want to know" (category (ii)) or because he regarded it as "none of his business" (category (iii)), that is quite another. Such conduct is dishonest, and those who are guilty of it cannot complain if, for the purpose of civil liability, they are treated as if they had actual knowledge.