Salmond on Jurisprudence is a legal classic and has been with students, the Bench and the Bar for the last seven decades. In this Summary, the original has been scrupulously followed and later developments are pointed out in footnotes. Stability and progress are the two main pillars of law. Expectations aroused by past experience over a period of time cannot be easily upset, otherwise social stability is undermined. On the other hand, the felt necessities of time can be disregarded by the legislator at the peril of the destruction of social structure itself. The interplay between these two ideologies – stability on one hand and social necessity on the other – is particularly visible in law making in India today.