Life assurance is the compound growth, first, of our commercial necessities, aided largely by a love of speculation, and later, of our progressive civilization. For the former, rough and ready means of estimation were resorted to; for the latter, a long and elaborate course of progressive investigation was needed.

The development of the business has extended over some three or four centuries, perhaps more. It has passed through three distinct phases, as (1). The Experimental Period; (2). The Speculative or Transitional Period; (3). The Period of Scientific Exactitude. These periods, of course, more or less overlap each other, but they each possess very marked distinctions.