An address giv­en Sep­tem­ber 14, 1952 by His Holi­ness Pope Pius XII to the First Inter­na­tion­al Con­gress on the Histopathol­o­gy of the Ner­vous System.

1. The “First Inter­na­tion­al Con­gress on the Histopathol­o­gy of the Ner­vous Sys­tem” has suc­ceed­ed in cov­er­ing a tru­ly vast amount of mate­r­i­al. Through detailed expla­na­tion and demon­stra­tion it had to put into exact per­spec­tive the caus­es and first begin­nings of the dis­eases of the ner­vous sys­tem prop­er­ly so called and of the dis­eases we call psy­chic. A report was read and an exchange of views held on recent ideas and dis­cov­er­ies con­cern­ing lesions of the brain and oth­er organs, which are the ori­gin and cause of ner­vous dis­eases as well as of psy­cho­path­ic ill­ness. These dis­cov­er­ies have been made, part­ly, through entire­ly new means and meth­ods. The num­ber and nation­al­i­ty of the par­tic­i­pants in the Con­gress, and espe­cial­ly of the speak­ers, show that spe­cial­ists of the most diverse coun­tries and nation­al­i­ties have exchanged expe­ri­ences for their own mutu­al ben­e­fit and to pro­mote the inter­ests of sci­ence, the inter­ests of the indi­vid­ual patient and the inter­ests of the community.

2. You do not expect Us to dis­cuss the med­ical ques­tions which con­cern you. Those are your domain. Dur­ing the past few days you have tak­en a gen­er­al view of the vast field of research and work which is yours. Now, in answer to the wish you your­selves have expressed, We want to draw your atten­tion to the lim­its of this field-not the lim­its of med­ical pos­si­bil­i­ties, of the­o­ret­i­cal and prac­ti­cal med­ical knowl­edge, but the lim­its of moral rights and duties. We wish to make Our­self the inter­preter of the moral con­science of the research work­er, the spe­cial­ist and the prac­tion­er and of the man and Chris­t­ian who fol­lows the same path.

3. In your reports and dis­cus­sions you have caught sight of many new roads, but there remain a num­ber of ques­tions still unsolved. The bold spir­it of research incites one to fol­low new­ly dis­cov­ered roads, to extend them, to cre­ate new ones and to renew meth­ods. A seri­ous, com­pe­tent doc­tor will often see with a sort of spon­ta­neous intu­ition the moral legal­i­ty of what he pro­pos­es to do and will act accord­ing to his con­science. But there are oth­er instances where he does not have this secu­ri­ty, where he may see or think he sees the con­trary with cer­tain­ty or where he doubts and wavers between Yes and No. In the most seri­ous and pro­found mat­ters, the man in the physi­cian is not con­tent with exam­in­ing from a med­ical point of view what he can attempt and suc­ceed in. He also wants to see his way clear­ly in regard to moral pos­si­bil­i­ties and obligations.

4. We would like to set forth briefly the essen­tial prin­ci­ples which per­mit an answer to be giv­en to this ques­tion. The appli­ca­tion to spe­cif­ic cas­es you will make your­selves in your role of doc­tor, because only the doc­tor under­stands the med­ical evi­dence thor­ough­ly both in itself and in its effects and because with­out exact knowl­edge of the med­ical facts it is impos­si­ble to deter­mine what moral prin­ci­ple applies to the treat­ment under dis­cus­sion. The doc­tor, there­fore, looks at the med­ical aspect of the case, the moral­ist, the laws of moral­i­ty. Ordi­nar­i­ly, when explained and com­plet­ed mutu­al­ly, the med­ical and moral evi­dence will make pos­si­ble a reli­able deci­sion as to the moral legal­i­ty of the case in all its con­crete aspects.

5. In order to jus­ti­fy the moral­i­ty of new pro­ce­dures, new attempts and meth­ods of research and med­ical treat­ment, three main prin­ci­ples must be kept in mind:

1) The inter­ests of med­ical science.

2) The inter­ests of the indi­vid­ual patient to be treated.

3) The inter­ests of the com­mu­ni­ty, the “bon­um commune.”

6. We ask whether these three inter­ests, tak­en singly or even togeth­er, have absolute val­ue in moti­vat­ing and jus­ti­fy­ing med­ical treat­ment or whether they are valid mere­ly with­in cer­tain deter­mined lim­its? In the lat­ter case, what are these lim­its? To this We shall try to give a brief answer.

I. The Inter­ests of Sci­ence as Jus­ti­fi­ca­tion for Research and the Use of New Methods.

7. Sci­en­tif­ic knowl­edge has its own val­ue in the domain of med­ical sci­ence no less than in oth­er sci­en­tif­ic domains, such as, for exam­ple, physics, chem­istry, cos­mol­o­gy and psy­chol­o­gy. It is a val­ue which must cer­tain­ly not be min­i­mized, a val­ue exist­ing quite inde­pen­dent­ly of the use­ful­ness or use of the acquired knowl­edge. More­over, knowl­edge as such and the full under­stand­ing of any truth raise no moral objec­tion. By virtue of this prin­ci­ple, research and the acqui­si­tion of truth for arriv­ing at new, wider and deep­er knowl­edge and under­stand­ing of the same truth are in them­selves in accor­dance with the moral order.

8. But this does not mean that all meth­ods, or any sin­gle method, arrived at by sci­en­tif­ic and tech­ni­cal research offers every moral guar­an­tee. Nor, more­over, does it mean that every method becomes lic­it because it increas­es and deep­ens our knowl­edge. Some­times it hap­pens that a method can­not be used with­out injur­ing the rights of oth­ers or with­out vio­lat­ing some moral rule of absolute val­ue. In such a case, although one right­ly envis­ages and pur­sues the increase of knowl­edge, moral­ly the method is not admis­si­ble. Why not? Because sci­ence is not the high­est val­ue, that to which all oth­er orders of val­ues-or in the same order of val­ue, all par­tic­u­lar val­ues-should be sub­or­di­nat­ed. Sci­ence itself, there­fore, as well as its research and acqui­si­tions, must be insert­ed in the order of val­ues. Here there are well defined lim­its which even med­ical sci­ence can­not trans­gress with­out vio­lat­ing high­er moral rules. The con­fi­den­tial rela­tions between doc­tor and patient, the per­son­al right of the patient to the life of his body and soul in its psy­chic and moral integri­ty are just some of the many val­ues supe­ri­or to sci­en­tif­ic inter­est. This point will become more obvi­ous as We proceed.

9. Although one must rec­og­nize in the “inter­ests of sci­ence” a true val­ue that the moral law allows man to pre­serve, increase and widen, one can­not con­cede the fol­low­ing state­ment: “Grant­ed, obvi­ous­ly, that the doctor’s inter­ven­tion is deter­mined by sci­en­tif­ic inter­est and that he observes the rules of his pro­fes­sion, there are no lim­its to the meth­ods for increas­ing and deep­en­ing med­ical sci­ence.” Even on this con­di­tion, one can­not just con­cede this principle.

II. The Inter­ests of the Patient as Jus­ti­fi­ca­tion of New Med­ical Meth­ods of Research and Treatment.

10. In this con­nec­tion, the basic con­sid­er­a­tions may be set out in the fol­low­ing form: “The med­ical treat­ment of the patient demands tak­ing a cer­tain step. This in itself proves its moral legal­i­ty.” Or else: “A cer­tain new method hith­er­to neglect­ed or lit­tle used will give pos­si­ble, prob­a­ble or sure results. All eth­i­cal con­sid­er­a­tions as to the lic­it­ness of this method are obso­lete and should be treat­ed as pointless.”

11. How can any­one fail to see that in these state­ments truth and false­hood are inter­min­gled? In a very large num­ber of cas­es the “inter­ests of the patient” do pro­vide the moral jus­ti­fi­ca­tion of the doctor’s con­duct. Here again, the ques­tion con­cerns the absolute val­ue of this prin­ci­ple. Does it prove by itself, does it make it evi­dent that what the doc­tor wants to do con­forms to the moral law?

12. In the first place it must be assumed that, as a pri­vate per­son, the doc­tor can take no mea­sure or try no course of action with­out the con­sent of the patient. The doc­tor has no oth­er rights or pow­er over the patient than those which the lat­ter gives him, explic­it­ly or implic­it­ly and tac­it­ly. On his side, the patient can­not con­fer rights he does not pos­sess. In this dis­cus­sion the deci­sive point is the moral lic­it­ness of the right a patient has to dis­pose of him­self. Here is the moral lim­it to the doctor’s action tak­en with the con­sent of the patient.

13. As for the patient, he is not absolute mas­ter of him­self, of his body or of his soul. He can­not, there­fore, freely dis­pose of him­self as he pleas­es. Even the rea­son for which he acts is of itself nei­ther suf­fi­cient nor deter­min­ing. The patient is bound to the imma­nent tele­ol­o­gy laid down by nature. He has the right of use, lim­it­ed by nat­ur­al final­i­ty, of the fac­ul­ties and pow­ers of his human nature. Because he is a user and not a pro­pri­etor, he does not have unlim­it­ed pow­er to destroy or muti­late his body and its func­tions. Nev­er­the­less, by virtue of the prin­ci­ple of total­i­ty, by virtue of his right to use the ser­vices of his organ­ism as a whole, the patient can allow indi­vid­ual parts to be destroyed or muti­lat­ed when and to the extent nec­es­sary for the good of his being as a whole. He may do so to ensure his being’s exis­tence and to avoid or, nat­u­ral­ly, to repair seri­ous and last­ing dam­age which can­not oth­er­wise be avoid­ed or repaired.

14. The patient, then, has no right to involve his phys­i­cal or psy­chic integri­ty in med­ical exper­i­ments or research when they entail seri­ous destruc­tion, muti­la­tion, wounds or per­ils. 15. More­over, in exer­cis­ing his right to dis­pose of him­self, his fac­ul­ties and his organs, the indi­vid­ual must observe the hier­ar­chy of the orders of val­ues-or with­in a sin­gle order of val­ues, the hier­ar­chy of par­tic­u­lar rights ‑inso­far as the rules of moral­i­ty demand. Thus, for exam­ple, a man can­not per­form on him­self or allow doc­tors to per­form acts of a phys­i­cal or somat­ic nature which doubt­less relieve heavy phys­i­cal or psy­chic bur­dens or infir­mi­ties, but which bring about at the same time per­ma­nent abo­li­tion or con­sid­er­able and durable diminu­tion of his free­dom, that is, of his human per­son­al­i­ty in its typ­i­cal and char­ac­ter­is­tic func­tion. Such an act degrades a man to the lev­el of a being react­ing only to acquired reflex­es or to a liv­ing automa­tion. The moral law does not allow such a rever­sal of val­ues. Here it sets up its lim­its to the “med­ical inter­ests of the patient.”

16. Here is anoth­er exam­ple. In order to rid him­self of repres­sions, inhi­bi­tions or psy­chic com­plex­es man is not free to arouse in him­self for ther­a­peu­tic pur­pos­es each and every appetite of a sex­u­al order which is being excit­ed or has been excit­ed in his being, appetites whose impure waves flood his uncon­scious or sub­con­scious mind. He can­not make them the object of his thoughts and ful­ly con­scious desires with all the shocks and reper­cus­sions such a process entails. For a man and a Chris­t­ian there is a law of integri­ty and per­son­al puri­ty, of self-respect, for­bid­ding him to plunge so deeply into the world of sex­u­al sug­ges­tions and ten­den­cies. Here the “med­ical and psy­chother­a­peu­tic inter­ests of the patient” find a moral lim­it. It is not proved-it is, in fact, incor­rect-that the pan­sex­u­al method of a cer­tain school of psy­cho­analy­sis is an indis­pens­able inte­grat­ing part of all psy­chother­a­py which is seri­ous and wor­thy of the name. It is not proved that past neglect of this method has caused grave psy­chic dam­age, errors in doc­trine and appli­ca­tion in edu­ca­tion, in psy­chother­a­py and still less in pas­toral prac­tice. It is not proved that it is urgent to fill this gap and to ini­ti­ate all those inter­est­ed in psy­chic ques­tions in its key ideas and even, if nec­es­sary, in the prac­ti­cal appli­ca­tion of this tech­nique of sexuality.

17. We speak this way because today these asser­tions are too often made with apo­d­ic­tic assur­ance. Where instincts are con­cerned it would be bet­ter to pay more atten­tion to indi­rect treat­ment and to the action of the con­scious psy­che on the whole of imag­i­na­tive and affec­tive activ­i­ty. This tech­nique avoids the devi­a­tions We have men­tioned. It tends to enlight­en, cure and guide; it also influ­ences the dynam­ic of sex­u­al­i­ty, on which peo­ple insist so much and which they say is to be found, or real­ly exists, in the uncon­scious or subconscious.

18. Up to now We have spo­ken direct­ly of the patient, not of the doc­tor. We have explained at what point the per­son­al right of the patient to dis­pose of him­self, his mind, his body, his fac­ul­ties, organs and func­tions, meets a moral lim­it. But at the same time We have answered the ques­tion: Where does the doc­tor find a moral lim­it in research into and use of new meth­ods and pro­ce­dures in the “inter­ests of the patient?” The lim­it is the same as that for the patient. It is that which is fixed by the judg­ment of sound rea­son, which is set by the demands of the nat­ur­al moral law, which is deduced from the nat­ur­al tele­ol­o­gy inscribed in beings and from the scale of val­ues expressed by the nature of things. The lim­it is the same for the doc­tor as for the patient because, as We have already said, the doc­tor as a pri­vate indi­vid­ual dis­pos­es only of the rights giv­en him by the patient and because the patient can give only what he him­self possesses.

19. What We say here must be extend­ed to the legal rep­re­sen­ta­tives of the per­son inca­pable of car­ing for him­self and his affairs: chil­dren below the age of rea­son, the fee­ble­mind­ed and the insane. These legal rep­re­sen­ta­tives, autho­rized by pri­vate deci­sion or by pub­lic author­i­ty have no oth­er rights over the body and life of those they rep­re­sent than those peo­ple would have them­selves if they were capa­ble. And they have those rights to the same extent. They can­not, there­fore, give the doc­tor per­mis­sion to dis­pose of them out­side those limits.

III. The Inter­ests of the Com­mu­ni­ty as Jus­ti­fi­ca­tion of New Med­ical Meth­ods of Research and Treatment.

20. For the moral jus­ti­fi­ca­tion of the doctor’s right to try new approach­es, new meth­ods and pro­ce­dures We invoke a third inter­est, the inter­est of the com­mu­ni­ty, of human soci­ety, the com­mon good or “bon­um com­mune,” as the philoso­pher and social stu­dent would say.

21. There is no doubt­ing the exis­tence of such a com­mon good. Nor can we ques­tion the fact that it calls for and jus­ti­fies fur­ther research. The two inter­ests of which We have already spo­ken, that of sci­ence and that of the patient, are close­ly allied to the gen­er­al interest.

22. Nev­er­the­less, for the third time we come back to the ques­tion: Is there any moral lim­it to the “med­ical inter­ests of the com­mu­ni­ty” in con­tent or exten­sion? Are there “full pow­ers” over the liv­ing man in every seri­ous med­ical case? Does it raise bar­ri­ers that are still valid in the inter­ests of sci­ence or the indi­vid­ual? Or, stat­ed dif­fer­ent­ly: Can pub­lic author­i­ty, on which rests respon­si­bil­i­ty for the com­mon good, give the doc­tor the pow­er to exper­i­ment on the indi­vid­ual in the inter­ests of sci­ence and the com­mu­ni­ty in order to dis­cov­er and try out new meth­ods and pro­ce­dures when these exper­i­ments trans­gress the right of the indi­vid­ual to dis­pose of him­self? In the inter­ests of the com­mu­ni­ty, can pub­lic author­i­ty real­ly lim­it or even sup­press the right of the indi­vid­ual over his body and life, his bod­i­ly and psy­chic integrity?

23. To fore­stall an objec­tion, We assume that it is a ques­tion of seri­ous research, of hon­est efforts to pro­mote the the­o­ry and prac­tice of med­i­cine, not of a maneu­ver serv­ing as a sci­en­tif­ic pre­text to mask oth­er ends and achieve them with impunity.

24. In regard to these ques­tions many peo­ple have been of the opin­ion and are still of the opin­ion today, that the answer must be in the affir­ma­tive. To give weight to their con­tention they cite the fact that the indi­vid­ual is sub­or­di­nat­ed to the com­mu­ni­ty, that the good of the indi­vid­ual must give way to the com­mon good and be sac­ri­ficed to it. They add that the sac­ri­fice of an indi­vid­ual for pur­pos­es of research and sci­en­tif­ic inves­ti­ga­tion prof­its the indi­vid­ual in the long run.

25. The great post­war tri­als brought to light a ter­ri­fy­ing num­ber of doc­u­ments tes­ti­fy­ing to the sac­ri­fice of the indi­vid­ual in the “med­ical inter­ests of the com­mu­ni­ty.” In the min­utes of these tri­als one finds tes­ti­mo­ny and reports show­ing how, with the con­sent and, at times, even under the for­mal order of pub­lic author­i­ty, cer­tain research cen­ters sys­tem­at­i­cal­ly demand­ed to be fur­nished with per­sons from con­cen­tra­tion camps for their med­ical exper­i­ments. One finds how they were deliv­ered to such cen­ters, so many men, so many women, so many for one exper­i­ment, so many for anoth­er. There are reports on the con­duct and the results of such exper­i­ments, of the sub­jec­tive and objec­tive symp­toms observed dur­ing the dif­fer­ent phas­es of the exper­i­ments. One can­not read these reports with­out feel­ing a pro­found com­pas­sion for the vic­tims, many of whom went to their deaths, and with­out being fright­ened by such an aber­ra­tion of the human mind and heart. But We can also add that those respon­si­ble for these atro­cious deeds did no more than to reply in the affir­ma­tive to the ques­tion We have asked and to accept the prac­ti­cal con­se­quences of their affirmation.

26. At this point is the inter­est of the indi­vid­ual sub­or­di­nat­ed to the community’s med­ical inter­ests, or is there here a trans­gres­sion, per­haps in good faith, against the most ele­men­tary demands of the nat­ur­al law, a trans­gres­sion that per­mits no med­ical research?

27. One would have to shut one’s eyes to real­i­ty to believe that at the present time one could find no one in the med­ical world to hold and defend the ideas that gave rise to the facts We have cit­ed. It is enough to fol­low for a short time the reports on med­ical efforts and exper­i­ments to con­vince one­self of the con­trary. Invol­un­tar­i­ly one asks one­self what has autho­rized, and what could ever autho­rize, any doctor’s dar­ing to try such an exper­i­ment. The exper­i­ment is described in all its stages and effects with calm objec­tiv­i­ty. What is ver­i­fied and what is not is not­ed. But there is not a word on its moral legal­i­ty. Nev­er­the­less, this ques­tion exists, and one can­not sup­press it by pass­ing it over in silence.

28. In the above men­tioned cas­es, inso­far as the moral jus­ti­fi­ca­tion of the exper­i­ments rests on the man­date of pub­lic author­i­ty, and there­fore on the sub­or­di­na­tion of the indi­vid­ual to the com­mu­ni­ty, of the individual’s wel­fare to the com­mon wel­fare, it is based on an erro­neous expla­na­tion of this prin­ci­ple. It must be not­ed that, in his per­son­al being, man is not final­ly ordered to use­ful­ness to soci­ety. On the con­trary, the com­mu­ni­ty exists for man.

29. The com­mu­ni­ty is the great means intend­ed by nature and God to reg­u­late the exchange of mutu­al needs and to aid each man to devel­op his per­son­al­i­ty ful­ly accord­ing to his indi­vid­ual and social abil­i­ties. Con­sid­ered as a whole, the com­mu­ni­ty is not a phys­i­cal uni­ty sub­sist­ing in itself and its indi­vid­ual mem­bers are not inte­gral parts of it. Con­sid­ered as a whole, the phys­i­cal organ­ism of liv­ing beings, of plants, ani­mals or man, has a uni­ty sub­sist­ing in itself. Each of the mem­bers, for exam­ple, the hand, the foot, the heart, the eye, is an inte­gral part des­tined by all its being to be insert­ed in the whole organ­ism. Out­side the organ­ism it has not, by its very nature, any sense, any final­i­ty. It is whol­ly absorbed by the total­i­ty of the organ­ism to which it is attached.

30. In the moral com­mu­ni­ty and in every organ­ism of a pure­ly moral char­ac­ter, it is an entire­ly dif­fer­ent sto­ry. Here the whole has no uni­ty sub­sist­ing in itself, but a sim­ple uni­ty of final­i­ty and action. In the com­mu­ni­ty indi­vid­u­als are mere­ly col­lab­o­ra­tors and instru­ments for the real­iza­tion of the com­mon end.

31. What results as far as the phys­i­cal organ­ism is con­cerned? The mas­ter and user of this organ­ism, which pos­sess­es a sub­sist­ing uni­ty, can dis­pose direct­ly and imme­di­ate­ly of inte­gral parts, mem­bers and organs with­in the scope of their nat­ur­al final­i­ty. He can also inter­vene, as often as and to the extent that the good of the whole demands, to par­a­lyze, destroy, muti­late and sep­a­rate the mem­bers. But, on the con­trary, when the whole has only a uni­ty of final­i­ty and action, its head-in the present case, the pub­lic author­i­ty-doubtless­ly holds direct author­i­ty and the right to make demands upon the activ­i­ties of the parts, but in no case can it dis­pose of its phys­i­cal being. Indeed, every direct attempt upon its essence con­sti­tutes an abuse of the pow­er of authority.

32. Now med­ical exper­i­ments-the sub­ject We are dis­cussing here imme­di­ate­ly and direct­ly affect the phys­i­cal being, either of the whole or of the sev­er­al organs, of the human organ­ism. But, by virtue of the prin­ci­ple We have cit­ed, pub­lic author­i­ty has no pow­er in this sphere. It can­not, there­fore, pass it on to research work­ers and doc­tors. It is from the State, how­ev­er, that the doc­tor must receive autho­riza­tion when he acts upon the organ­ism of the indi­vid­ual in the “inter­ests of the com­mu­ni­ty.” For then he does not act as a pri­vate indi­vid­ual, but as a manda­to­ry of the pub­lic pow­er. The lat­ter can­not, how­ev­er, pass on a right that it does not pos­sess, save in the case already men­tioned when it acts as a deputy, as the legal rep­re­sen­ta­tive of a minor for as long as he can­not make his own deci­sions, of a per­son of fee­ble mind or of a lunatic.

33. Even when it is a ques­tion of the exe­cu­tion of a con­demned man, the State does not dis­pose of the individual’s right to life. In this case it is reserved to the pub­lic pow­er to deprive the con­demned per­son of the enjoy­ment of life in expi­a­tion of his crime when, by his crime, he has already dis­posed him­self of his right to live.

34. We can­not refrain from explain­ing once more the point treat­ed in this third part in the light of the prin­ci­ple to which one cus­tom­ar­i­ly appeals in like cas­es. We mean the prin­ci­ple of total­i­ty. This prin­ci­ple asserts that the part exists for the whole and that, con­se­quent­ly, the good of the part remains sub­or­di­nat­ed to the good of the whole, that the whole is a deter­min­ing fac­tor for the part and can dis­pose of it in its own inter­est. This prin­ci­ple flows from the essence of ideas and things and must, there­fore, have an absolute value.

35. We respect the prin­ci­ple of total­i­ty in itself but, in order to be able to apply it cor­rect­ly, one must always explain cer­tain premis­es first. The basic premise is that of clar­i­fy­ing the quaes­tio fac­to, the ques­tion of fact. Are the objects to which the prin­ci­ple is applied in the rela­tion of a whole to its parts? A sec­ond premise is the clar­i­fi­ca­tion of the nature, exten­sion and lim­i­ta­tion of this rela­tion­ship. Is it on the lev­el of essence or mere­ly on that of action, or on both? Does it apply to the part under a cer­tain aspect or in all its rela­tions? And, in the field where it applies, does it absorb the part com­plete­ly or still leave it a lim­it­ed final­i­ty, a lim­it­ed inde­pen­dence? The answers to these ques­tions can nev­er be inferred from the prin­ci­ple of total­i­ty itself. That would be a vicious cir­cle. They must be drawn from oth­er facts and oth­er knowl­edge. The prin­ci­ple of total­i­ty itself affirms only this: where the rela­tion­ship of a whole to its part holds good, and in the exact mea­sure it holds good, the part is sub­or­di­nat­ed to the whole and the whole, in its own inter­est, can dis­pose of the part. Too often, unfor­tu­nate­ly, in invok­ing the prin­ci­ple of total­i­ty, peo­ple leave these con­sid­er­a­tions aside, not only in the field of the­o­ret­i­cal study and the field of appli­ca­tion of law, soci­ol­o­gy, physics, biol­o­gy and med­i­cine, but also of log­ic, psy­chol­o­gy and metaphysics.

36. Our plan was to draw your atten­tion to cer­tain prin­ci­ples of deon­tol­ogy which define the lim­its and con­fines of research and exper­i­men­ta­tion in regard to new med­ical meth­ods to be imme­di­ate­ly applied to liv­ing men.

37. In the domain of your sci­ence it is an obvi­ous law that the appli­ca­tion of new meth­ods to liv­ing men must be pre­ced­ed by research on cadav­ers or the mod­el of study and exper­i­men­ta­tion on ani­mals. Some­times, how­ev­er, this pro­ce­dure is found to be impos­si­ble, insuf­fi­cient or not fea­si­ble from a prac­ti­cal point of view. In this case, med­ical research will try to work on its imme­di­ate object, the liv­ing man, in the inter­ests of sci­ence, in the inter­ests of the patient and in the inter­ests of the com­mu­ni­ty. Such a pro­ce­dure is not to be reject­ed with­out fur­ther con­sid­er­a­tion. But you must stop at the lim­its laid down by the moral prin­ci­ples We have explained.

38. With­out doubt, before giv­ing moral autho­riza­tion to the use of new meth­ods, one can­not ask that any dan­ger or any risk be exclud­ed. That would exceed human pos­si­bil­i­ties, par­a­lyze all seri­ous sci­en­tif­ic research and very fre­quent­ly be to the detri­ment of the patient. In these cas­es the weigh­ing of the dan­ger must be left to the judg­ment of the tried and com­pe­tent doc­tor. Nev­er­the­less, as Our expla­na­tion has shown, there is a degree of dan­ger that moral­i­ty can­not allow. In doubt­ful cas­es, when means already known have failed, it may hap­pen that a new method still insuf­fi­cient­ly tried offers, togeth­er with very dan­ger­ous ele­ments, appre­cia­ble chances of suc­cess. If the patient gives his con­sent, the use of the pro­ce­dure in ques­tion is lic­it. But this way of act­ing can­not be upheld as a line of con­duct in nor­mal cases.

39. Peo­ple will per­haps object that the ideas set forth here present a seri­ous obsta­cle to sci­en­tif­ic research and work. Nev­er­the­less, the lim­its We have out­lined are not by def­i­n­i­tion an obsta­cle to progress. The field of med­i­cine can­not be dif­fer­ent in this respect from oth­er fields of man’s research, inves­ti­ga­tions and work. The great moral demands force the impetu­ous flow of human thought and will to flow, like water from the moun­tains, into cer­tain chan­nels. They con­tain the flow to increase its effi­cien­cy and use­ful­ness. They dam it so that it does not over­flow and cause rav­ages that can nev­er be com­pen­sat­ed for by the spe­cial good it seeks. In appear­ance, moral demands are a brake. In fact, they con­tribute to the best and most beau­ti­ful of what man has pro­duced for sci­ence, the indi­vid­ual and the community.

40. May Almighty God in His benev­o­lent Prov­i­dence give you His bless­ing and grace to this end.