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Letter 12610

Preston, S. T. to Darwin, C. R.

20 May 1880


Thanks for CD’s comments on his paper [“On a point relating to brain dynamics”, Nature 22 (1880): 29–30].

Contends that self-interest as a motive for conduct is more salutary than is generally thought, and should be considered in the evolution of morality.


25 Reedworth Street | Kennington SE. London

May 20th. 1880

Dear Sir

I thank you much for your letter and kindness in expressing opinions on my paper. There is however one point I should like to allude to, & which appears not to have conveyed quite the meaning I had intended—and which is from fault of inadequacy of expression on my part. I had meant the words “bound” in intelligence, “rapid” advance &c to possess a relative signification: i.e. in reference to the great length of period corresponding to man’s antiquity. My main object was to call more particular attention to certain causes, which, if they alone acted, would seem to conduce to a progressive rise in the development of brain structure.

No doubt secondary causes (such as change of climate, of geological conditions, conquest of a people &c &c) are also in action; sometimes in favour of progress, sometimes the reverse—and it would appear to me possible that the effects of these secondary causes would be those most noticed within so relatively short a period as 3 to 4000 years (say some 60 to 80 generations), and that therefore no reliable idea could probably be got of the average rate of progress of man by contemplating that period (i.e. the historical period). The remarks in your letter have however shown me that a still closer study of the subject (which appears an interesting one) would be desirable; and also an additional perusal of works relating thereto, which circumstances have not permitted me to do so much as I should have liked.

In reading recently again your work on “The Descent of Man”, I have been much interested in the part relating to the Evolution of morality. Having made this subject a special study for the last 2 or 3 years, I should like to make a few remarks, which I need not say have been very carefully considered, and which in view of the interest of the subject, might not perhaps be thought unworthy of attention.

It has appeared to me that the supposed undesirability of making Self or Self Interest the standard of morality is in reality questionable: and that the natural striving to avoid this seemingly undesirable conclusion has unconsciously (as it were) somewhat biassed the judgment in the careful search after truth—though one would of course wish to avoid any bias. To me it seems quite impossible to conceive a motive for an action which does not affect Self in some way: or in the form of an axiom (and most fundamental truths, it may be observed, are founded on axioms) it may be said that ‘a man cannot be affected by anything which does not affect himself (or touch his own individuality)’.

It will probably be admitted so far, that man has few instincts now (for external actions) which he cannot at least test by the light of his reason so as to see whether they are desirable or not— at any rate it would not be a thing to be wished that man should be dominated by instinct (i.e. without rational motive). Now (as I venture to submit) the only rational—and even only possible—motive for an action (which is not instinctive or random) is Self or Self-Interest. A man asks himself before taking any course (i.e. if he is rational and weighs his actions)—“how does this course affect my interests”? I would even maintain (as it is known that some able minds have done) that he could not act without this (i.e. not rationally). For that which does not affect him (or touch his individuality) cannot make him act (or is not a motive). “Sympathy”—which it will be admitted is a mere phrase (or effect)—only can affect a man because it affects Self: and I would even venture to contend that it is desirable that this should be so. For where would friendship (or love) be without Self on each side? (I think the meaning of this will be gathered, though mode of expression on subjects of this kind is not always easy) Self Interest is (in my contention) the very essence of love or friendship. Is it not because of the pleasure felt (self-interest) on each side that friendship is a desirable thing? Remove the element of Self (the pleasure enjoyed) from each side, and where is the friendship (or the love)? Could there be friendship without interest? In the same line of argument—could a really “disinterested” action be said to be worthy of praise? (meaning by this a mere instinctive or random action). Is it not rather because of the self-interest (or the element of Self in the action) that praise is deserved? A man helps another because he takes pleasure in the esteem of that man (or of mankind generally). Because that was his object, he deserved the praise and esteem all the more: for he thus deliberately earned it.

On the other hand, if that had not been his object, he would have deserved nothing—or (in other words), a person who acted without any motive of Self, could not deserve any praise, because he acted by mere instinct or at random; and consequently could have undergone no sacrifice. The more strongly the value of the praise and esteem of others is weighed beforehand, and balanced against the disadvantage of the sacrifice, the greater will the sacrifice be, and consequently the more will the reward be deserved.

To sum up therefore, I would contend that Self-Interest as a motive for conduct is a thing to be commended—and it certainly is I think (at least I may conscientiously say that this is very clear to my mind) the only conceivable rational motive of conduct: and always is the tacitly recognised motive in all rational actions. The effect “sympathy” or sociability then shows itself to be the highest form of Self-Interest. Perhaps it may not be thought out of place if I state here that in my own experience on the subject of Morality, some errors have been so perseveringly drilled (as it were) or impressed on the brain for centuries that it becomes far more difficult to unlearn than to learn, and it is only after the most persistent thought that errors are discovered, which one afterwards wonders could have escaped detection so long.

I think it admits of being clearly proved that that desirable consummation, the greatest happiness (or interest) of the greatest number, can only be attained by each one consulting his own happiness (or interests)—and that consequently Morality is not in any way opposed to perfect individual Liberty.

One of the points which has tended to prevent the general adoption of a common standard of Morality is (as it seems to me probable) the supposed idea that Self-Interest and Selfishness are synonymous. Whereas it may become clearly apparent on analysis, that Selfishness (or the attempt to advance oneself at the expense of others) is the very opposite of Self-Interest—from the fact that Sociability is one of the highest forms of Self-Interest (on account of the immense advantages gained therefrom). The apparent ease with which the Evolution of Morality would take place on the basis of Self-Interest, is perhaps too obvious to need special comment.

I cannot avoid the conclusion that the extraordinary circumstance of no universally recognised standard of conduct existing—in spite of the immense advance of the other sciences—has been greatly due to the supposed bugbear attaching to Self-Interest (or to the mistaking of this for Selfishness). In fact it is notorious that many great minds have felt themselves inevitably gravitating towards Self Interest as the natural standard of morality, but its fitness has apparently escaped them; or they have been frightened at the result—and the very ingenuity (sometimes almost desperate) of the efforts made to evade this deduction, are themselves surely among the best illustrations of its truth. It has been thought that if everyone were to follow his own interests, he would be in continual strife with his neighbours—forgetting that Sociability may be one of the strongest elements in Self-Interest. Hobbes (as Lange well relates in his “Geschichte des Materialismus”) was unable to contend against the logical conclusion that Self Interest was the motive of conduct: and he designed a scheme (as is known) by which the State was to have the dogmatic control over Morality—so as to prevent Self-Interest from causing people to “tear each other in pieces”. In examining the question carefully, it will become apparent, I think, that the neglect to identify Morality with Self-Interest has caused great evils. It has acted as the greatest discouragement to Virtue by making it appear against ones interests, and has given rise to the invention of those dogmas (such as that evident injustice eternal punishment) as supposed checks—and the inculcation of which may do so much harm to the young (especially when of inquiring minds). If it were invariably taught that the path of virtue, or strict integrity, was absolutely in accordance with Self-Interest, (in fact that virtue is its own reward), and that thieving or deceit were to be avoided because they were against ones interests: instead of the absurd statement that they are “wicked” (which only makes them more attractive, from the intangible nature of the reason)—I am convinced that immense good would result. In fact it would be doing no more than making morality stand upon Reason—its only sure basis.

I have ventured to go into these points, on account of the time and attention I have devoted to the subject (with the former valuable co-operation of a friend). As the matter is an interesting one, I need not say that if the conclusions carefully thought out, should be deemed worthy of consideration, I should much esteem anything you might like to remark on the subject—though quite at your leisure and wish: as I should not like this letter to have any appearance of presuming on your kindness in commenting upon my last paper.

I am | Your’s truly | S Tolver Preston

Charles Darwin Esqre F R S &c—

DAR 174: 61


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