Science,according to him,must rest upon facts.It must apply to real things,and to things which have definite relations and a common measure.Now,if anything be real,pains and pleasures are real.The expectation of pain or pleasure determines conduct;and,if so,it must be the sole determinant of conduct.The attempt to conceal or evade this truth is the fatal source of all equivocation and confusion.Try the experiment.Introduce a 'moral sense.'What is its relation to the desire for happiness?If the dictates of the moral sense be treated as ultimate,an absolutely arbitrary element is introduced;and we have One of the 'innate ideas'exploded by Locke,a belief summarily intruded into the system without definite relations to any other beliefs:a dogmatic assertion which refuses to be tested or to be correlated with other dogmas;a reduction therefore of the whole system to chaos.It is at best an instinctive belief which requires to be justified and corrected by reference to some other criterion.Or resolve morality into 'reason,'that is,into some purely logical truth,and it then remains in the air --a mere nonentity until experience has supplied some material upon which it can work.Deny the principle of utility,in short,as he says in a vigorous passage,(10)and you are involved in a hopeless circle.Sooner or later you appeal to an arbitrary and despotic principle and find that you have substituted words for thoughts.
The only escape from this circle is the frank admission that happiness is,in fact,the sole aim of man.There are,of course,different kinds of happiness as there are different kinds of physical forces.But the motives to action are,like the physical forces,commensurable.Two courses of conduct can always be compared in respect of the happiness produced,as two motions of a body can be compared in respect of the energy expended.If,then,we take the moral judgment to be simply a judgment of amounts of happiness,the whole theory can be systematised,and its various theorems ranged under a single axiom or consistent set of axioms.Pain and pleasure give the real value of actions;they are the currency with a definite standard into which every general rule may be translated.There is always a common measure applicable in every formula for the estimation of conduct.If you admit your Moral Sense,you profess to settle values by some standard which has no definite relation to the standard which in fact governs the normal transactions.But any such double standard,in which the two measures are absolutely incommensurable,leads straight to chaos.Or,if again you appeal to reason in the abstract,you are attempting to settle an account by pure arithmetic without reference to the units upon which your operation is performed.Two pounds and two pounds will make four pounds whatever a pound may be;but till I know what it is,the result is nugatory.Somewhere I must come upon a basis of fact,if my whole construction is to stand.
This is the fundamental position implied in Bentham's doctrine.The moral judgment is simply one case of the judgment of happiness.Bentham is so much convinced of this that to him there appeared to be in reality no other theory.
What passed for theories were mere combinations of words.Having said this,we know where to lay the foundations of the new science.It deals with a vast complicity of facts:it requires 'investigations as severe as mathematical ones,but beyond all comparison more intricate and extensive.'(11)Still it deals with facts,and with facts which have a common measure,and can,therefore,be presented as a coherent system.To present this system,or so much of it as is required for purposes of legislation,is therefore his next task.The partial execution is the chief substance of the Introduction.
Right and wrong conduct,we may now take for granted,mean simply those classes of conduct which are conducive to or opposed to happiness;or,in the sacred formula,to act rightly means to promote the greatest happiness of the greatest number.The legislator,like every one else,acts rightly in so far is he is guided by the principle (to use one of the phrases joined by Bentham)of 'maximising'happiness.He seeks to affect conduct;and conduct can be affected only by annexing pains or pleasures to given classes of actions.
Hence we have a vitally important part of his doctrine --the theory of 'sanctions.'
Pains and pleasures as annexed to action are called 'sanctions.'There are 'physical or natural,''political,''moral or popular,'and 'religious'sanctions.
The 'physical'sanctions are such pleasures and pains as follow a given course of conduct independently of the interference of any other human or supernatural being;the 'political'those which are annexed by the action of the legislator.
The 'moral or popular'those which are annexed by other individuals not acting in a corporate capacity;and the 'religious'those which are annexed by a 'superior invisible being,'or,as he says elsewhere,(12)'such as are capable of being expected at the lands of an invisible Ruler of the Universe.'the three last sanctions,he remarks,'operate through the first.'The 'magistrate'or 'men at large'can only operate,and God is supposed only to operate,'through the powers of nature,'that is,by applying some of the pains and pleasures which may also be natural sanctions.A man is burnt:if by his own imprudence,that is a 'physical'sanction;if by the magistrate,it is a 'political'sanction;if by some neglect of his neighbours,due to their dislike of his 'moral character,'a 'moral'sanction;if by the immediate act of God or by distraction caused by dread of God's displeasure,it is a 'religious'sanction.Of these,as Bentham characteristically observes(13)in later writing the political is much stronger than the 'moral'or 'religious.'