Now, I agree with Mill in holding that the scientific study of the structures and functions of the different governments that have actually existed i… - Henry Sidgwick

[T]he history of thought […] reveal[s] discrepancy between the intuitions of one age and those of a subsequent generation. But where the conflicting beliefs are not contemporaneous, it is usually not clear that the earlier thinker would have maintained his conviction if confronted by the arguments of the later. The history of thought, however, I need hardly say, affords abundant instances of similar conflict among contemporaries; and as conversions are extremely rare in philosophical controversy, I suppose the conflict in most cases affects intuitions—what is self-evident to one mind is not so to another. It is obvious that in any such conflict there must be error on one side or the other, or on both. The natural man will often decide unhesitatingly that the error is on the other side. But it is manifest that a philosophic mind cannot do this, unless it can prove independently that the conflicting intuitor has an inferior faculty of envisaging truth in general or this kind of truth; one who cannot do this must reasonably submit to a loss of confidence in any intuition of his own that thus is found to conflict with another’s.

Is it total or average happiness that we seek to make a maximum?...we foresee as possible that an increase in [population] numbers will be accompanied by a decrease in average happiness...if we take Utilitarianism to prescribe, as the ultimate end of action, happiness on the whole...it would follow that, if the additional population enjoy on the whole positive happiness, we ought to weigh the amount of happiness gained by the extra number against the amount lost by the remainder. So that, strictly conceived, the point up to which, on Utilitarian principles, population ought to be encouraged to increase, is not that at which average happiness is the greatest possible...but that at which the product formed by multiplying the number of persons living into the amount of average happiness reaches its maximum.

[T]he inhuman severity of the paradox that ‘pleasure and pain are indifferent to the wise man,’ never failed to have a repellent effect; and the imaginary rack on which an imaginary sage had to be maintained in perfect happiness, was at any rate a dangerous instrument of dialectical torment or the actual philosopher. Christianity extricated the moral consciousness from this dilemma between base subserviency and inhuman indifference to the feelings of the moral agent. It compromised the long conflict between Virtue and Pleasure, by transferring to another world the fullest realisation of both; thus enabling orthodox morality to assert itself, as reasonable and natural, without denying the concurrent reasonableness and naturalness of the individual’s desire for bliss without allow.