The Wealth of Nations by Part 1 Chapter 10 Page 27

In order to make insurance, either from fire or sea-risk, a trade at all, the common premium must be sufficient to compensate the common losses, to pay the expense of management, and to afford such a profit as might have been drawn from an equal capital employed in any common trade. The person who pays no more than this evidently pays no more than the real value of the risk, or the lowest price at which he can reasonably expect to insure it.

But though many people have made a little money by insurance, very few have made a great fortune; and from this consideration alone, it seems evident enough that the ordinary balance of profit and loss is not more advantageous in this than in other common trades by which so many people make fortunes. Moderate, however, as the premium of insurance commonly is, many people despise the