The individual can therefore be confidently recommended _always_ to conform to rules which are both generally useful and generally practised. In the case of rules of which the general observance _would_ be useful but does not exist, or of rules which are generally practised but which are not useful, no such universal recommendations can be made. In many cases the sanctions attached may be decisive in favour of conformity to the existing custom. But it seems worth pointing out that, even apart from these, the general utility of an action most commonly depends upon the fact that it is generally practised: in a society where certain kinds of theft are the common rule, the utility of abstinence from such theft on the part of a single individual becomes exceedingly doubtful, even though the common rule is a bad one. There is, therefore, a strong probability in favour of adherence to an existing custom, even if it be a bad one. But we cannot, in this case, assert with any confidence that this probability is always greater than that of the individual’s power to judge that an exception will be useful; since we are here supposing certain one relevant fact--namely, that the rule, which he proposes to follow, _would_ be better than that which he proposes to break, _if_ it were generally observed. Consequently the effect of his example, so far as it tends to break down the existing custom, will here be for the good. The cases, where another rule would certainly be better than that generally observed, are, however, according to what was said above, very rare; and cases of doubt, which are those which arise most frequently, carry us into the next division of our subject. =100.= (β) This next division consists in the discussion of the method by which an individual should decide what to do with regard to possible actions of which the general utility cannot be proved. And it should be observed, that, according to our previous conclusions, this discussion will cover almost all actions, except those which, in our present state of society, are generally practised. For it has been urged that a proof of general utility is so difficult, that it can hardly be conclusive except in a very few cases. It is certainly not possible with regard to all actions which _are_ generally practised; though here, if the sanctions are sufficiently strong, they are sufficient by themselves to prove the general utility of the individual’s conformity to custom. And if it is possible to prove a general utility in the case of some actions, _not_ generally practised, it is certainly not possible to do so by the ordinary method, which tries to shew in them a tendency to that preservation of society, which is itself a mere means, but only by the method, by which in any case, as will be urged, the individual ought to guide his judgment--namely, by shewing their direct tendency to produce what is good in itself or to prevent what is bad.