CHAPTER I.

INTRODUCTORY.

(1) IT is a recommendation of the prince of ancient philosophers, when treating on a subject not unconnected with the one under consideration, that our suppositions should be possibilities';" which, in an argument that has so much to do with futurity, and is necessarily governed by so many contingent events, is hardly less important than the rule, which ought to be universal under all circumstances,-that our statements should be truths. It is much to be regretted that neither of these maxims has been sufficiently attended to by the advocates of the prevailing theory of population, even in treating upon those essential points on which the question manifestly depends. We have already seen, that, had the population of the American colonies, in the earlier periods of their history, been carefully ascertained from existing documents of an official character, and faithfully presented to the public, accompanied by an account of the extraneous accessions which it has perpetually received, (a course which none can deny ought to have been adopted,) the utter irreconcileableness of its rate of increase with any geometrical ratio whatsoever, would have become instantly apparent, and the sole proof, therefore, upon which the entire theory rests, overturned. I now proceed to shew, for a still higher purpose than that of adding confirmation to a conclu

1 Aristot. De Repub. 1. ii. c. 4.

sion already so fully demonstrated, that, even in those parts of the system under examination, which seem to rest upon calculation, the grossest errors, often, indeed, involving impossibilities, prevail; and that, not on points of little moment, but on the most important and fundamental positions.

(2) The present Book of this treatise will, therefore, be devoted to the detection of some of the more important of these errors and miscalculations, beginning with the rates of doubling, so confidently put forth, as natural to an unchecked population. Due examination will shew, beyond the possibility of doubt, that the periods of duplication assigned by the anti-populationists, as those in which mankind would increase if unchecked, and even the longest of them, which they repeatedly assure us prevails at the present moment in the United States of America, are, in every instance, and under the most favourable circumstances, impossibilities. The same will be proved of any geometric ratio of human increase whatsoever. The effect of emigration on population; the supposed prevalence of the preventive check in this and other countries; the effect of mortalities on the number of marriages, and of scarcities on their prolificness, with several other subjects essential to the theory under consideration, will also be separately examined; when, it is believed, a series of errors will be exhibited rarely equalled, in either number or magnitude, in any system which has met with such general attention. The Book will conclude with some remarks on the incorrectness of any opinion formed concerning the future increase of population, by that which has apparently taken place during the present century.

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CHAPTER II.

OF THE POSSIBLE PERIODS OF HUMAN DUPLICATION.

(1) It becomes necessary to examine, with attention, the supposed ratios of human increase, as, notwithstanding we are repeatedly told that the "evils of "population" are in present and perpetual operation, still we are emphatically referred to the future for their more complete development. These ratios invest the Principle of Population, as lately expounded, with its prospective terrors, and furnish the panoply of the theory. It is by these, that this inexorable system, after having pronounced what it presumes to be the sentence of Nature, warns the human race of its speedy execution. In the fears thus excited, the reason and experience of mankind are silenced, and even the evidence of their senses disregarded: a little time may, therefore, not be misapplied in reducing this political bugbear, thus exaggerated by fear and ignorance, to its proper dimensions, previously to its being shewn to be a phantom altogether. It will then be seen, that if any geometric ratio of human increase did exist as a law of nature, still it would be of a very different character from any of those now put forth, affording mankind ample time to contemplate the event, and provide for its consequences.

(2) In proceeding, therefore, to the examination of some of the fundamental errors in the calculations of the theory I am combating, for the twofold purpose of still further shaking the confidence of the public in a notion so hostile to their well being, and

of preparing the way for a contrary principle of population about to be developed, I shall commence with the supposed periods of doubling, so confidently relied upon by our anti-populationists, and so perpetually asserted by them as matters of fact; without the least attempt to prove them within the range of possibilities.

(3) In pursuing this branch of the inquiry, I shall principally confine my remarks to the elaborate work on population so often referred to, in which indeed the assertions of previous writers on the same side of the question are very faithfully copied, and, I regret to add, the opinions of others but too frequently misinterpreted. Generally speaking, there is a considerable degree of indefiniteness in the expressions of its author in reference to these various terms of doubling, not, as it should seem, from any apprehension of exaggerating the rates of human increase, but rather from a reluctance to acknowledge the quickest of them equal in effect to the unchecked power of the principle for which he contends. In the commencement of his work, however, he gives forth a ratio of increase sufficiently rapid to satisfy the most sanguine on the subject, in these words: "Sir William Petty'supposes a doubling possible in so short a space as "ten years.

(4) The credit of Sir William Petty demands, that this quotation from him should be accompanied by his own explanation. His supposition is a mere comment upon some observations in the then recent work of Major Graunt upon the Bills of Mortality, and the hypothesis demands, that every female between the age of fifteen and forty-four should "bear a child once in two years;" and, moreover, that the deaths should be only one fifth part as numerous as the