A few things about Whewell's general moral approach first, which (because he, like most of the thinkers of his day, thinks of ethics as a moral science) is part of his general approach to the sciences. Whewell takes all human thought to have two aspects, which he usually calls Fact and Conception. (Talking about two aspects, though, can be potentially misleading, because Whewell thinks there can be levels: Facts + Conception can become a new Fact to be linked with other Facts by a new Conception. However, he thinks that at every level these two aspects can be distinguished.) When our Conceptions are so general that they are highly stable and unify a vast number of Facts, he calls them Ideas; some examples of Ideas are Resemblance, Cause, Number, and Space. We can formulate Fundamental Principles to capture how these Ideas unify Facts into an intelligible whole; these principles can be refined over time to take into account more and more Facts. The physical sciences as Whewell sees them proceed by observing the world around us in light of these Fundamental Principles, and by uniting Facts through the Principle to discover specific Laws of Nature. Moral sciences have the same structure, with Moral Ideas, Fundamental Principles, and Laws of Human Action, but the way we get Laws of Human Action is different from the way we get Laws of Nature. To get Laws of Nature we start with Facts and find Conceptions under which we can use the Fundamental Principles to organize them; to get Laws of Human Action we start with the Fundamental Principles and find the Laws, then reorganize the Facts to fit the Laws. In other words, physical sciences fit Laws to Facts; moral sciences fit Facts to Laws.
Whewell proposes that there are five main Moral Ideas: Benevolence, Justice, Truth, Purity, and Order. From these spring Conceptions that give us our entire vocabulary of virtue. Each Moral Idea has its Fundamental Principle, which serves as an axiom for ethics in the same way that Fundamental Principles of Space and Time serve as axioms for physics.
|Benevolence||Man is to be loved as man.|
|Justice||Each man is to have his own.|
|Truth||We must conform to the universal understanding among men implied by language.|
|Purity||The lower parts of our nature are to be governed by, and subservient to, the higher parts.|
|Order||We must obey positive laws as the necessary conditions of morality.|
There are, in addition to these a number of Fundamental Principles for especially important Conceptions that assist in applying these to human action.
The Moral Idea that concerns us is that of Purity, along with its Fundamental Principle. It takes very little perusal of Book III, Chapter X of The Elements of Morality, which discusses the duties of Purity, to recognize that this subordination of the lower to the higher is exactly what is meant when older authors speak of temperance regulating pleasures according to what is necessary for human life. (And that Whewell knows this is confirmed by the virtues and vices he associated with it.) Indulgence in the desire for food and drink, for instance, is to be regulated so as to support "life, strength, and cheerfulness, and the cultivation of the social affections". Desires in general are to be subordinated to genuine affection, and blind affection is to be subordinated to moral sentiments.
Whewell notes, however, that some modern moralists reject any distinction of higher and lower in human nature (section 320):
The distinction of the Lower and Higher Parts of our Nature, by means of which we express the Principle of Purity, has been rejected by some moralists, and has been termed Declamation. Such moralists contend that pleasure is universally and necessarily the object of human action; and that human pleasures do not differ in kind, but only in intensity and duration: so that, according to these teachers, there is no difference of superior and inferior, between the pleasures of appetite, the pleasures of affection, and the pleasure of doing good. Hence, say they, the only difference in the character of actions, is their being better or worse means of obtaining pleasure.
This is exactly Bentham's view, and even if we could not recognize it from the description, the use of the word 'Declamation' would be enough to establish it: it's one of Bentham's most withering insults to call things mere declamation. Thus Whewell recognizes the opposition between Benthamism and the doctrine of temperance. He argues that we should follow Butler rather than Bentham on this point; there is a systematic order in human nature requiring that one thing govern another. If we follow Bentham rather than Butler, we end up destroying any distinction between man and beast and making it impossible to draw a coherent distinction between crime and error (fault and mistake), since they both just end up being miscalculations in the pursuit of pleasure. What is more, we make morality itself incoherent:
According to this doctrine, we can have no Supreme Rule of Action; for if pleasure be the highest object of action, it is also the lowest. With such opinions, we deprive the words right and wrong of their common meaning; for to men in general, they do not mean right and wrong roads to enjoyment, which this view makes them mean.
Whewell notes, for instance, that the pursuit of moral progress itself suggests that there is a higher end than pleasure, and that we know by experience that, while people primarily pursuing moral progress can have pleasure, people primarily pursuing pleasure tend simply to give up on pursuing moral progress. Whewell goes farther than this in his criticism, though. In discussing the kind of love that leads to marriage, he says (section 327):
The Love which looks forwards to the conjugal union, includes a reverence for the conjugal condition, and all its circumstances. Such a love produces in the mind a kind of moral illumination, which shows the lover how foul a thing mere lust is; and makes him see, as a self-evident truth, that affection is requisite to purify desire, and virtue necessary to purify affection.
Thus certain kinds of love inherently involve subordinating the lower to the higher, and those who love in this way are positioned to see that the Principle of Purity is a necessary feature of a good life.