But even this rule is far from being sufficient: for personal merit is not everything; is not the only element to be considered; age, length of service, have also their value; for, in order that the State be well served, it is necessary that those who work for it, should have faith in the future; should know that their past services will be taken account of, that as they grow older and their burdens heavier, the State will come to their assistance in raising their functions. Thus must length of service be combined with merit and be itself a part of the merit. In many administrations, the division between these two elements is made by granting vacant posts half to length of service, half to choice. But the choice itself depends on various elements; for personal merit is itself composed of many elements: for example, which should be considered the higher, talent or work? A lively mind will accomplish more work in less time; but it may be negligent, forgetful, disorderly: a substantial mind, always ready, industrious, conscientious, offers better guarantees and more security; yet in difficult transactions, talent offers more resources. This shows how many practical difficulties have to be met in the choice of men. It is for experience and conscience to decide in each particular case. Morality can give no general rules, except negative rules: to avoid _nepotism_, _simony_,[44] guard against the arbitrary, against favor, testimonials, etc. In examinations there are the same dangers to avoid: for here, also, it is unfortunately too much a general belief that favoritism is the rule, and that testimonials go for everything. The first duty is to set aside all personal interest, worldly influence, pressure from without. But all does not end here; for there remains to be seen what rule is to be followed in the choice of candidates. If the number of those who are to be elected is fixed beforehand, as in contests, there is then already a great difficulty obviated: for there is but to be determined the order of merit of the candidates. But in many examinations the number is not fixed. It becomes then necessary to find a just medium between excess of severity and excess of indulgence. This medium is generally determined through the co-operation of different minds, of which some are inclined to severity and others to indulgence. But one must not trust to this co-operation of others to arrive at a strict justice. It is clear that each, for his own part, must fix upon a mean, and endeavor to adhere to it as strictly as possible. In cases where there is occasion for classification, one must, above all, consider the more substantial qualities, and not allow one's self to be too easily led away by mere appearances and surface-talent.