impulse which dies away if it is not indulged?  How far can it be eliminated or modified by education?  Is it satisfied by a leasehold or a life-interest, or by such an arrangement of corporate property as is offered by a collegiate foundation, or by the provision of a public park?  Does it require for its satisfaction material and visible things such as land or houses, or is the holding, say, of colonial railway shares sufficient?  Is the absence of unlimited proprietary rights felt more strongly in the case of personal chattels (such as furniture and ornaments) than in the case of land or machinery?  Does the degree and direction of the instinct markedly differ among different individuals or races, or between the two sexes?

Pending such an inquiry my own provisional opinion is that, like a good many instincts of very early evolutionary origin, it can be satisfied by an avowed pretence; just as a kitten which is fed regularly on milk can be kept in good health if it is allowed to indulge its hunting instinct by playing with a bobbin, and a peaceful civil servant satisfies his instinct of combat and adventure at golf.  If this is so, and if it is considered for other reasons undesirable to satisfy the property instinct by the possession, say, of slaves or of freehold land, one supposes that a good deal of the feeling of property may in the future be enjoyed even by persons in whom the instinct is abnormally strong, through the collection of shells or of picture postcards.

The property instinct is, it happens, one of two instances in which the classical economists deserted their usual habit of treating all desires as the result of a calculation of the means of obtaining ‘utility’ or ‘wealth.’  The satisfaction of the instinct of absolute property by peasant proprietorship turned, they said, ‘sand to gold,’ although it required a larger expenditure of labour for every unit of income than was the case in salaried employment.  The other instance was the instinct of family affection.  This also still needs a special treatise on its stimulus, variation, and limitations.  But the classical economists treated it as absolute and unvarying.  The ‘economic man,’ who had no more concern than a lone wolf with the rest of the human species, was treated as possessing a perfect and permanent solidarity of feeling with his ‘family.’  The family was apparently assumed as consisting of those persons for whose support a man in Western Europe is legally responsible, and no attempt was made to estimate whether the instinct extended in any degree to cousins or great uncles.

A treatise on political impulses which aimed at completeness would further include at least the fighting instinct (with the part which it plays, together with affection and loyalty, in the formation of parties), and the instincts of suspicion, curiosity, and the desire to excel.