14. The words "any right privilege obligation or liability acquired accrued or incurred", which the Acts Interpretation Act uses, and the same words when used by judges, are all general and abstract terms. Each of them could be the heading of a chapter in a work of analytical jurisprudence. Section 5 (1) speaks of the employer being "liable to pay compensation". The word "liable" here at once attracts the idea of a "liability". But it is not necessary to be a disciple of Hohfeld, or wedded to the terminology of his analysis of legal rights and duties, to see that both words are, using his phrase, "chameleon-hued". And it is necessary to be cautious in going from the word "liable" as used in s. 5 (1) to the word "liability" as used in other contexts. "Liability" can be, and often is, used as a synonym for "duty" or "obligation" ; but Sir George Paton in his book Jurisprudence, 3rd ed. (1964), by Professor Derham p. 242, uses it in an opposed sense. "Obligation", he says, "should be sharply distinguished from liability. Obligation relates to what a person ought to do because there is a duty laid upon him : liability to what he must do because he has failed to do what he ought." The term "liabilities" when used to describe unpaid debts reflects this meaning. For Salmond and Hohfeld "liability" has still another meaning. It describes a person's liability to be, by the power of someone else, made subject to a duty. In that sense it is the opposite of "immunity". It seems to me that without descending to too much refinement there are at least three main senses in which lawyers speak of a liability or liabilities. The first, a legal obligation or duty : the second the consequence of a breach of such an obligation or duty : the third a situation in which a duty or obligation can arise as the result of the occurrence of some act or event. It is in the third sense that s. 5 (1) speaks of an employer as liable to pay compensation in accordance with the Act. But I do not think it is the sense in which it is said that an amending Act does not disturb existing liabilities arising out of past transactions. That to my mind describes a liability having become complete by past events rather than a situation in which some future event must occur to make the effect of past events create a completed liability. The position was put in the first edition of Halsbury's Laws of England, vol. 20, p. 153, as follows : "The liability to pay compensation under the Workmen's Compensation Act attaches to the relation of employer and workman, and is quite irrespective of negligence . . . . it is an obligation placed upon every employer of labour to make pecuniary compensation to a limited extent, whenever death or disablement happens to a workman in the course of his employment." The obligation "to pay compensation in accordance with the Act" arises when incapacity or death ensues from the injury - and, in the case of death, only if the worker leaves dependants. It is said that s. 5 (1), speaking as it does from the happening of the injury, by its reference to a liability to pay in accordance with the Act means that the pecuniary liability, if it should thereafter arise, is to be quantified in accordance with those provisions, that they measure the limit of a contingent liability ; and thus create an immunity against its increase not disturbed by the amending Act. The argument is powerful, but I have come to the conclusion that it puts too much weight upon the words "in accordance with the provisions of this Act". The amending Act gives these words a new content of meaning as from the date it came into force. In reading the Act after 1965 in relation to the liability in respect of deaths thereafter, we ought I think to read s. 5 (1) when it speaks of "compensation in accordance with this Act" as speaking of this Act as amended : cf. Rattan Singh v. Commissioner of Income Tax (1967) 1 WLR 625 . Lord Tenterden C.J. in Surtees v. Ellison (1829) 9 B & C 750, at p 752 [1829] EngR 594; (109 ER 278, at p 279) , said : "It has been long established, that, when an Act of Parliament is repealed, it must be considered (except as to transactions past and closed) as if it had never existed." The only matter which was past and closed when the 1965 Act came into operation was, it seems to me, that the worker had suffered an injury of a kind which, if death ensued, would entitle his dependants to compensation. An alteration of the definition of "injury" would not alter this (in the absence of an express provision that it should do so). But when the Act of 1965 came into operation it provided a new measure of the actual pecuniary liability of the employer which would arise when a worker died leaving dependants. Whether the present respondent can have the benefit of the new measure depends upon ascertaining, by permissible means, the intention of the Parliament of Victoria. It is to be decided, I think, by bearing in mind that the amendment was enacted to take its place in an existing and continuing system of workers' compensation law, and to be construed in the light of s. 5 (3) of the Acts Interpretation Act. (at p585)