Such considerations as these have led some political thinkers to hold that Justice requires a mode of distributing payment for services, entirely different from that at present effected by free competition: and that all labourers ought to be paid according to the intrinsic value of their labour as estimated by enlightened and competent judges. If the Socialistic Ideal--as we may perhaps call it--could be realised without counter-balancing evils, it would certainly seem to give a nearer approximation to what we conceive as Divine Justice than the present state of society affords. But this supposes that we have found the rational method of determining value: which, however, is still to seek. Shall we say that these judges are to take the value of a service as proportionate to the amount of happiness produced by it? If so, the calculation is, of course, exposed to all the difficulties of the hedonistic method discussed in Book ii.: but supposing these can be overcome, it is still hard to say how we are to compare the value of different services that must necessarily be combined to produce happy life. For example, how shall we compare the respective values of necessaries and luxuries? for we may be more sensible of the enjoyment derived from the latter, but we could not have this at all without the former. And, again, when different kinds of labour co-operate in the same production, how are we to estimate their relative values? for even if all mere unskilled labour may be brought to a common standard, this seems almost impossible in the case of different kinds of skill. For how shall we compare the labour of design with that of achievement? or the supervision of the whole with the execution of details? or the labour of actually producing with that of educating producers? or the service of the _savant_ who discovers a new principle, with that of the inventor who applies it?