For the members of the voluntary association numerous obligations arise from their membership. The association may require, as a condition of membership, the agreement to perform certain services,--for instance, "jury service."[733] And "inasmuch as Anarchistic associations recognize the right of secession, they may utilize the ballot, if they see fit to do so. If the question decided by ballot is so vital that the minority thinks it more important to carry out its own views than to preserve common action, the minority can withdraw. In no case can a minority, however small, be governed without its consent."[734] The voluntary association is entitled to compel its members to live up to their obligations. "If a man makes an agreement with men, the latter may combine to hold him to his agreement";[735] therefore a voluntary association is "entitled to enforce whatever regulations the contracting parties may agree upon."[736] To be sure, one must bear in mind that "very likely the best way to secure the fulfilment of promises is to have it understood in advance that the fulfilment is not to be enforced."[737] Of especial importance among the obligations of the members of a voluntary association is the duty of paying taxes; but the tax is voluntary by virtue of the fact that it is based on contract.[738] "Voluntary taxation, far from impairing the association's credit, would strengthen it";[739] for, in the first place, because of the simplicity of its functions, the association seldom or never has to borrow; in the second place, it cannot, like the present State upon its basis of compulsory taxation, repudiate its debts and still continue business; and, in the third place, it will necessarily be more intent on maintaining its credit by paying its debts than is the State which enforces taxation.[740] And furthermore, the voluntariness of the tax has this advantage, that "the defensive institution will be steadily deterred from becoming an invasive institution through fear that the voluntary contributions will fall off; it will have this constant motive to keep itself trimmed down to the popular demand."[741]