HISTORICAL 19 



which it was the object of his book to demonstrate. Among these 

 he mentions Plato and Aristotle. In these cases Malthus was too 

 anxious to attribute the first enunciation of the ' principle ' to 

 others. It was only owing to the very peculiar circumstances of 

 Greek life that the problem ever arose at all. A consideration of 

 the ideal city state involved the question as to what was the most 

 desirable number of citizens. This point occupied Plato's atten- 

 tion, and in one place he deals with it in detail. There should be, 

 he says, 5,040 citizens in the state.^ In the Bepuhlic he explained 

 that the number of citizens was to be kept about the same by 

 a strict regulation of unions. ^ In the Laws, however, no such 

 system is advocated, and he discusses the possibility of a failure to 

 maintain the number.^ He appears to think that various checks 

 such as infanticide and ' inundations ' will keep numbers close to 

 the desirable level ; if too great an increase takes place, then 

 recourse must be had to emigration. It does not seem that the 

 problem was ever approached more closely in Greek literature. 



References to this subject by Roman authors are confined for 

 the most part to laments over the infertility of the old Roman 

 stock. That which drew the attention of the Romans to the 

 subject was thus a peculiar phase of the problem, and the views 

 expressed by them were in consequence usually limited to the 

 search for a remedy for a particular weakness in national 

 life. As we shall point out later, it is doubtful how far infertility 

 was characteristic of all classes ; that it was not widespread seems 

 incidentally to be indicated in the following curious passage fiom 

 Tertullian in which he is led to express views reminiscent of many 

 modern contributions to the subject. Tertullian is confuting the 

 Pythagorean theory of the transmigration of souls, and argues 

 that, if it were true, the number of men must remain unchanged. 

 But, he says, this is obviously not so ; population continually 

 increases. This leads him to refer to the state of contemporary 

 civihzation. ' We find ', he says, ' in the records of the Antiquities 

 of Man * that the human race has progressed with a gradual growth 

 of population. . . . Surely it is obvious enough, if one looks at the 

 whole world, that it is becoming better cultivated and more fully 

 peopled than anciently. All places are now accessible, all are well 

 known, all open to commerce ; most pleasant farms have obliterated 



> Plato, Laws, v. 737. ^ piato, Republic, v. 460. ^ Plato, Laws, v. 740. 



* This is apparently a reference to a work by Varro. 



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