To establish a joint-stock company, however, for any undertaking, merely because such a company might be capable of managing it successfully; or, to exempt a particular set of dealers from some of the general laws which take place with regard to all their neighbours, merely because they might be capable of thriving, if they had such an exemption, would certainly not be reasonable. To render such an establishment perfectly reasonable, with the circumstance of being reducible to strict rule and method, two other circumstances ought to concur. First, it ought to appear with the clearest evidence, that the undertaking is of greater and more general utility than the greater part of common trades; and, secondly, that it requires a greater capital than can easily be collected into a private copartnery. If a moderate capital were sufficient, the great utility of the undertaking would not be a sufficient reason for establishing a joint-stock company; because, in this case, the demand for what it was to produce, would readily and easily be supplied by private adventurers. In the four trades above mentioned, both those circumstances concur.
The great and general utility of the banking trade, when prudently managed, has been fully explained in the second book of this Inquiry. But a public bank, which is to support public credit, and, upon particular emergencies, to advance to government the whole produce of a tax, to the amount, perhaps, of several millions, a year or two before it comes in, requires a greater capital than can easily be collected into any private copartnery.
The trade of insurance gives great security to the fortunes of private people, and, by dividing among a great many that loss which would ruin an individual, makes it fall light and easy upon the whole society. In order to give this security, however, it is necessary that the insurers should have a very large capital. Before the establishment of the two joint-stock companies for insurance in London, a list, it is said, was laid before the attorney-general, of one hundred and fifty private usurers, who had failed in the course of a few years.