This address was delivered before the Mont Pelerin Society at St. Moritz, Switzerland, on September 4, 1957, and published by the Freedom School in 1958. Harper, an economist at Cornell, was the author of Liberty: A Path to Its Recovery and Why Wages Rise. He later founded the Institute for Humane Studies.
There are times when one's humility seems to go on vacation, as it did, for me when Professor Hayek proposed tackling this topic for discussion. Then later when reality returned to plague the victim, there ended a beautiful, balmy sense of well-being during which all had seemed perfectly clear and simple; during which the topic of liberty — its meaning and philosophic base — posed no apparent problem of a serious nature; during which, at first blush, it seemed almost trite to presume to dwell on the obvious.
But is the meaning of liberty so clear and simple?
Were a stranger to observe the nature of the Mont Pelerin Society and note its convening for this decennial occasion, would he not be surprised to find us devoting an entire session to the meaning of liberty — the word perhaps more basic than any other to the original purpose of the Society? Might he not expect this to have been a matter resolved with essentially unanimous agreement at the outset of our Societal association together? The fact that it has not been thus resolved seems to me to reflect the lack of any clear agreement as to the meaning of liberty; apparently it is something not so clear and simple. We use this beloved word in our communication with one another and assume an understanding that apparently is not there.
Confusion over the meaning of this key word may seem strange. For liberty is not a new issue in the world. Presumably it has been a concern of mankind from the very dawn of his existence. As he battled for life and life's betterment, he must surely have faced constant threats to his liberty, just as he was confronted with the tides, the tornadoes, and pestilences of all sorts. All these must have been a part of man's experience from time immemorial.
Prior to any carefully reasoned contemplation of such obstructions, mankind must have battled them intuitively. We may assume that for an eon mankind has battled for his liberty, for instance, without having any deep sense of what liberty really is, just as he battled for his existence among the forces of nature without knowing precisely and formally the laws of natural phenomena.
I suppose that conclaves are also being held elsewhere to ponder just what electricity really is, or where and why the winds and storms originate, while we here are, pondering just what liberty really is. We are to explore the composition of liberty and its deeper meaning at a time when the paths of mankind behind us are strewn with the blood of countless battles over it throughout all of history.
So my comments on this subject are offered in the spirit of exploration rather than with any presumed finality, and I trust they will be accepted in that light.
The Nature of Man
At the outset we might recognize two outstanding, long-standing questions:
- What is the nature of man?
- What pathways are charted for man, as a consequence of his nature? What, in other words, is the purpose of human life?
As to the nature of man, I readily give my proxy to others, including not only the philosophers but also the biologists whose field of search must hold an important key to the nature of man as it relates to the problem of liberty. For if the biological nature of the organism is not in tune with liberty, it is surely futile for us to proclaim the virtues of liberty and to pursue its practice; and in that event we had best disband this Society and redirect our hopes and endeavors elsewhere.
But I assume the nature of man to be attuned to liberty. And therefore I posit the case for liberty squarely on a biological base, using that term in its broadest sense to include all that is man. Work in biology and related fields in recent years suggests the promise of a highly fruitful period which may now be dawning. Illustrative of work which seems to me to be highly significant in relation to the nature of man and liberty is that of Roger J. Williams, biochemist at the University of Texas  ; Edward W. Sinnott, botanist and Emeritus Dean of the Graduate School at Yale University  ; Horace W. Stunkard, Emeritus Head of Biology Department at New York University  ; Leonard Carmichael, Secretary of the Smithsonian Institution  ; Lecomte du Nouy, the French scientist  ; and others.
The outstanding theme of works such as these, so far as liberty is concerned, is the extreme diversity of persons, one from another, and the significance of this variation when liberty allows its expression in life's attainments.
Among these infinitely variable qualities evidencing the nature of man is variation in his knowledge and wisdom, or in his ignorance and foolishness. Liberty tends to enthrone knowledge and wisdom; the absence of liberty tends to enthrone ignorance and foolishness, because of the mathematical principle of regression which comes into play through the processes by which liberty is curbed.
Another derivative of biological research is to bring into focus the independent, unitary nature of the human organism. Persons are born alone as distinctly separate units, one at a time. They likewise die one at a time as separate units. All their acts in between are as separate units as well, even in their cooperative endeavors. An aggregation of any sort — even this meeting — fails to blend even two persons into one unit, so long as there is life in each. Even in panic or any like phenomenon where the herd seems to operate as a unit, it is entirely individual persons who do all the acting, however much their apparent concert. Every collective is an illusory construction. The biologists are helping us to see this and to relegate the concepts of the social collective, to where nothing is left except an empty, meaningless shell of imaginary form.
With that brief treatment of the assumption that liberty is rooted in the biological nature of man, perhaps we should consider what is the meaning of this liberty of which we speak.
In searching for its meaning one might first turn to what many consider to be the opposite of liberty, namely, socialism. Could we not merely invert the definition of socialism and have an acceptable definition of liberty?
One can search in vain, I believe, for any consensus of the meaning of socialism. The confusion is illustrated by the fact that when the Parisian Le Figaro opened its pages in 1892 with a list of definitions of socialism, more than 600 were included. And when Dan Griffiths of England wrote his book in 1924, What is Socialism?, he found 263 answers worthy of note.
I shudder at the thought of proposing 600 or even 263 corresponding counterparts of these as definitions of liberty, for you to pay your money and take your choice. I believe that it is necessary for effective communication and progress in the cause of liberty that we bring into focus a more precise tool of word meaning than that. One wonders, to use an analogy, what would be the present status of science in general if there had been no more precise language there; if, for instance, one were to find 600 or 263 possible answers offered to the problem of the sum of two and two, or the nature of oxygen?
Nor can I quite accept the view of one renowned social scientist who recently opined that it is a good thing to have the meaning of words changing constantly "progressing" — as though words were somehow like clothes which become soiled and need changing every now and then. Nineteen Eighty-Four portrayed the consequences of that practice.
Both precision and stability of the meaning of words like liberty seem absolutely required for much progress in the science of human relationships. For communication is surely as important here as in other sciences, and communication requires both precision and stability in the meaning of words.
I suppose the supreme liberty of all is for each person to be allowed to define liberty as he pleases. I am, therefore, going to exercise that privilege myself. In doing so, however, I would like to make it as reasonable as possible in order that others may share my view of an etymologically and functionally sound definition.
To begin with, liberty seems to me to be a word having to do with matters of personal conduct in relation to other persons in society. Or to put it another way, it relates to limitations of action one person may or may not suffer at the hands of another person. It is in that sense a word focused on matters of individual conduct in a social setting.
There are other barriers to one's freedom of action, of, course, besides those one person imposes upon another. These include environmental restraints imposed by nature other than by persons — chemical, physical, astronomical, and other such barriers to complete freedom of action.
You may, for instance, desire to move elsewhere without being confronted with the mountain which stands in your way. Or in winter you may wish roses to rise out of the snow. Or you may wish Mars were closely at hand so that you could step across for a visit. Such impediments to the fulfillment of our momentary wishes are not problems of liberty. They lie outside the interpersonal concerns where all problems of liberty are to be found, for they are problems you would face even in total isolation from your fellow men.
Liberty stems from liber, which means to be free. And so the definition of liberty I would propose is this:
Liberty is the absence of coercion of a human being by any other human being; it is a condition where the person may do whatever he desires, according to his wisdom and conscience.
This means that to have liberty one must be free without qualification or modification, so far as his social relationships are concerned. Nature will still impose its restrictions on him, of course, but his fellow men shall impose none.
In order to bring this definition more dearly into focus, consider as an alternative a definition which seems to me to be the only possible one to be selected in its stead:
Liberty is a condition where the person must do whatever another person desires that he shall do, according to the other person's wisdom and conscience.
This is the sole, alternative, because for any one act under consideration there are only two possibilities: (1) you determine what you shall do; or (2) you are prohibited from determining what you shall do.
The last of these two possibilities means that some other person or persons will decide what you shall do, and force you to do it. That seems to be a definition of slavery rather than of liberty, and therefore I must reject it. And since there is no other alternative — since a person must act voluntarily by his own wisdom and conscience or involuntarily according to the mandate of another person — the first definition seems to me to be the only tenable one.
One point of possible concern with this definition should be mentioned at this point. Liberty as I have defined it does not preclude as guidance for one's acts any form or degree of advice and influence, if voluntarily accepted, which, originates elsewhere than within himself. This guidance might be religious influences, evidence from historical records, scientific knowledge, the advice of another person, or even processes of mental telepathy or clairvoyance or insight from mystical origins, to whatever extent these may occur. If willingly accepted, the act resulting from such influences is as much an act of liberty as would be any other.
So liberty as I have defined it is not limited to self-willed conduct arising from total isolation. All these other forces can operate to influence one's acts as a free man. I would even argue that such influences operate at their best and their fullest only under liberty.
Adulterated Definitions of Liberty
Many persons have an overpowering urge to modify and adulterate this definition of liberty. These include many persons who seem to have unusually deep libertarian perceptions. They want a definition that encompasses u201Cproper conduct.u201D To do so, however, seems to me to confuse the concept of liberty and to adulterate it until it becomes meaningless.
Many persons, I suspect, have such an infatuation for their beloved word liberty that, like a juvenile lover whose expectations surpass reality, they try to deny any imperfection in their beloved. And so, in order to assure his perfection they try to deny the possibility of any imperfection by their definition. In this instance, some would bend their concept of liberty so as to exclude any act which in their eyes is imperfect.
Let us consider in an analogy another field of contemplation, chemistry. In the early period of its development, it was perceived that the elemental chemical constituents must be identified before a science of chemistry could be developed. Suppose it had been decided at that time to define each element as that form of material only when it was being put to u201Cproper use.u201D Chlorine would then, I suppose, be chlorine when used for table salt, but something else when used for chlorine gas for wartime or something else if the enemy used it for that purpose, I suppose, and something else if the salt were to corrode your motor. The introduction of any such dilution of meaning of the underlying concepts of any science would seem to bar effectively any appreciable development of that science. Basic words of this type must not be confused by trying to incorporate human judgments of an entirely different sort.
Or suppose similar confusions had been introduced into the early development of words for basic concepts in physics, Or physiology, or bacteriology. What then could have been the progress in those fields?
I would argue, then, for this clear and rigid meaning of a key word of social science — liberty.
It should acquire a place in our vocabulary comparable to an element in chemistry, or to motion in physics. For if we try to modify it with the presumed propriety of the act, we shall have introduced a wholly different type of concern which should be kept entirely separate from the meaning of liberty. For they are two areas which cannot possibly be blended into one clear definition.
One other aspect of this definition seems worth mentioning. Were we to try to incorporate into the definition of liberty a judgment of the act as good or bad making liberty, in other words, mean only u201Cgoodu201D acts — who, or what body, is to define what is u201Cgoodu201D? I would contend that the determination of what is good would then have to be a socialized one in some degree. And for us as libertarians to define liberty in such a way that we must accept a socialized concept of morals before we can classify an act as one of liberty would seem to me to be an abandonment of our faith in the formulating of our own language.
Another alternative meaning of liberty, differing from the one I prefer, is to define it as a condition where the restriction of coercion of human beings by other human beings is at a minimum. But such a concept, in my opinion, describes something else than liberty. Perhaps it is the way to describe a liberal society of fallible humans, or something of the sort. For in such a society of fallible humans, complete liberty of all its members is obviously an impossibility, for our fallible conduct precludes some of the liberty of one another.
We would not define a vacuum as the nearest to the absence of material content of a space that we know how to attain, nor would we define ytterbium as a compound as near to that element in its purity as we have yet found. Instead, we should define all these liberty, vacuum, ytterbium — in pure form even when unattained yet in our experience.
Your choice is still an act of choice even when I do not agree with your selection. Your act of liberty, likewise, is still liberty when I disfavor what you have done. It is an act of liberty for me to define liberty in a manner you disfavor; it is also an act of liberty for you to disagree.
Morals versus Liberty
In defining liberty as embodying judgments of one's own acts according to his conscience, my intent is to recognize the importance of morals and ethics in this connection. Rather than to attempt to distinguish between morals and ethics in the short time available, I shall speak only of morals — the u201Cgoodu201D versus the u201Cevil,u201D the u201Coughtsu201D versus the u201Cought notsu201D of human conduct.
It is well to remind ourselves at this point that liberty as I have defined it is not a synonym for good; that any act of liberty may be either u201Cgoodu201D or u201Cevilu201D as another person judges it. This will be true until and unless infinite wisdom and universal perfection of conscience guide every act of every person in such a way as to be approved by every other person.
But universal agreement is far from a description of real life; it is no more than a direction toward which to strive. And that fact is precisely why there is any problem of liberty at all. Except as there exist these differences in moral judgments of what the other person ought or ought not do, there would be no purpose whatever in a Mont Pelerin Society, nor any other of the processes aimed at trying to deal with matters of human conduct and conflict
To speak of morals, then, is not the same as speaking of liberty, but instead refers to a qualitative measure of those acts.
Let us explore this point just a bit further. The concern of morals is to judge acts as either good or evil, right or wrong — u201Cmoralu201D or u201Cimmoral,u201D as we say in appraising them. Such a judgment has neither place nor meaning except for acts of choice. A person cannot do right except in a situation where there is also the option of doing wrong. In other words, moral considerations have no place except where liberty exists. A stone is confronted with no moral consideration, because so far as we know a stone is wholly without choice and merely rolls here and there with the impact of the forces of its natural environment. A stone can do no right or wrong under its own guidance because it makes no choices — it is incapable of liberty.
It follows, then, that no problem of morals can ever be resolved by removing liberty, in a degree either large or small. All that can be done by enslavement is to remove the moral consideration from the enslaved person's life, and relegate him toward the status of a stone. The moral issue remains with the enslaver, however.
To assert that a person or a society of persons can be made moral by removing their liberty is akin to the policy of the doting mother who said that she was not going to let her child go near the water until he had learned to swim.
Thomas Davidson expressed it this way: u201CThat which is not free is not responsible, and that which is not responsible is not moral. In other words, freedom is the condition of morality.u201D 
Liberty will be allowed in society only insofar as there is acceptance of the conduct of others. Acceptance may be because of either agreement with the act or tolerance in disagreement.
Tolerance in disagreement demands acceptance of separate domains within which a person is allowed to make his mistakes, if he does so with what is his rather than with what is yours. Private property within the economic arena of scarce and desired things operates to this end. Once these domains are accepted, then it becomes a prime moral right of a person u201Cto do what I will with mine ownu201D instead of to do what I will with your own. 
Some moral code to guide our acts, insofar as acceptance can be attained, is a route to peaceful coexistence with one another. And for that reason the moral code becomes a concern related to the question of maximizing liberty, because in the absence of such agreement we shall surely take liberty away from one another more or less in proportion thereto.
Where and how do we look for a code of this sort?
A basic question involved here, it seems to me, is whether one assumes that there is an ordered universe or assumes that there is not.
If we start with the assumption of an ordered universe, certain other derivative assumptions follow in turn. The assumption of an ordered universe, as I see it, allows room for both science and religion, as companions representing two types of belief about the nature of an ordered universe. This assumption of order is theistic in one or another form, whether one wishes to think of it as God, or as natural law, or as the universal phenomenon of cause or consequence, or what-not. For present purposes we need not differentiate in any such way as to beliefs, nor to carry the concept of God to the point of anthropomorphic or other. The only concern for this purpose is that of an ordered universe or not.
If one starts with the premise of an ordered universe, it follows that he accepts the existence of eternal truths and unchanging principles, universally. This does not necessitate the arrogant assumption that we know all these truths with final or full certainty; it means only the assumption that they exist to be found — that known or unknown to us, we are powerless to change them either individually or collectively, bending or altering them at will.
If there are these eternal truths and unchanging principles, then one may assume the existence, as a part of the universe in which we live, of moral truths — moral law, if one wishes to speak of them that way, ruling over and above our social, statutory laws of society, or custom, or tradition. These moral laws are then assumed to be the code of conduct by which to abide, if one is to be u201Cgood,u201D just as we assume that we must abide by physical laws if we are to be safe. Violation of either is an option under choice, or under liberty, but the consequences prevail in spite of our ignorance or our wishing that things were different in the universe.
If, on the other hand, one assumes the alternative of an unordered universe, his course of derived assumptions are these: atheism; events occurring at random; lack of any precise cause and consequence to be discovered; lack of eternal truths and unchanging principles; no moral law or physical law to rule affairs; no science to be pursued in the spirit that identical conditions will lead to consequences repeating themselves. It presumes, I suppose, that we can change the universe any way we want to, at will — but also, it seems to me, it assumes that no change will remain even for an instant. This whole concept seems to me to be a blind path to a dead end. I do not see how one can live under any such assumption. Study of science or of any past experiences of any sort would be a pure waste of time. One might as well jump off the cliff, if he were to assume that past events, involving untold numbers of deaths of persons who did likewise, prescribe no pattern for the present or the future.
So my assumption is an ordered universe, with moral law beyond the power of man to alter. We may not know what these moral laws are with certainty, but even so we must, under this assumption, proceed with the best guess we can make as to what they are. We would deny as moral truths any prescription by majority decision, or kingly decree, or the like — we would deny all these as invalid sources per se. We would reject the definition of morality given in a book by a Professor of Psychology at the University of Southern California, who has said: u201CMorality is the quality of behaving in the way society approves…u201D  Instead, we would accept morality as the quality of behavior by which an individual should abide, by a source of truth above the crowd.
It has always seemed to me in this connection that if there is cause and consequence in the area of morals, the accumulated experience of mankind must somehow be distilled into some sort of guide to conduct. It may be in part intuitive, like one's sense of fear at the edge of a cliff; it may be in the form of religion, or custom, or tradition, or what-not. We must admit, however, that these lessons of the past have been contaminated with error, including the medicine man's hocus-pocus and superstition of all sorts. But somewhere must be reflected the distilled experience of mankind in relation to moral law, to be found with some degree of validity if we will only look in the right place.
Let us take religion as an example. The Golden Rule and the Decalogue, for instance, have occurred in essentially the same way repeatedly in various religious eras and sects. It seems unlikely that this is due to chance, and therefore one may assume that concepts of this sort, to illustrate the process, persist because of their harmony in some degree with moral law of the universe.
My only point for purposes of the present discussion is to uphold a search for moral law, and to illustrate the type of thing that successful search may in time reveal.
The Rights of Man
In living our daily lives and making the decisions that liberty entails, one must assume certain human rights in accord with moral law. These human rights are not the sort of rights prescribed by a political body or by the toleration of one’s neighbors. They are, instead, the rights which moral law prescribes as the scope of propriety, if one is to avoid suffering a consequence as unfortunate in a moral sense as walking off a cliff or other such conduct would be in the world of nonhuman affairs.
What might such human rights be?
In a sense, perhaps, the most basic human right is the right to be free, the right to make choices and decisions, and to shoulder the consequences of the choice; the right to be wrong at times. I prefer, however, to start at another point in order to place a moral boundary on one's conduct under liberty.
Basic among human rights would seem to be the right to life itself. This is an assumption, of course. Like anything else we presume to know, if we trail liberty to the horizon of our view it will always be found to start with an assumption. Then derivatives flow logically from the beginning assumption, but with a validity no better than the validity of the premise.
The right to life as an assumption is evidenced by the way people act. It is evidenced by the way a person struggles to preserve his own life, as well as by one's reaction to a deed such as the murder of a baby. Before judging such a murder to be a dastardly deed which violates a basic human right to life, who among us would first inquire who perpetrated the murder; who would ask, as being relevant to such a judgment, whether it was done by the King, or by the Prime Minister, or by the Legislature, or by the majority in a national election? The seeming irrelevancy of such a query about the murderer reflects an acceptance, it seems to me, of the right to life as perhaps the basic human right of all. And others follow in its wake:
- The right to life.
- If one has the right to life, he then has the right to sustain his life with his own time and means, so long as in so doing he does not infringe on the same right of others.
- If one has the right to thus sustain his life, he then has the right to have whatever he is able to produce with his own time and means.
- If he has the right to whatever he is able to produce, he then has the right to keep it for any period of time the right of private property.
- If he has the right of private property, he then has the right to exchange it, sell it, or give it away on any terms acceptable to the recipient. No third party, be it one person or any combination of persons, has any right to intercede in the process or dictate its terms.
This, as I see it, is the sequence of rights which flows from the assumption of a right to life.
If this rigid code of rights seems harsh and inhumane, leaving persons destitute in any society abiding by it, I would reiterate that the final right of any person is the right of giving to others that which is his, as alms. Where else could alms come from for purposes of charity, if we are to avoid a sequence of rights that would lead logically to a denial of the right of life itself? Is charity to be founded on a denial of the right to life? I would argue that true charity can flow only from the fruits of production in the form of private property.
Assuming such a code of human rights, and relating it to religious codes, it is interesting to note the harmony between them. Such harmony is not proof, of course; it is no more than circumstantial evidence of validity. But even so, the Commandment u201CThou shalt not killu201D corresponds with the right to life, as a basic human right. The Commandment u201CThou shalt not stealu201D corresponds to the right to keep what one has produced or otherwise properly acquired as private property. Stealing is an empty word without the presumption of ownership, by the victim of the theft, of the object stolen. I have attempted to define liberty, and to give a philosophic base for liberty that recognizes both the importance and the content of morality, to the end that liberty may be maximized. Morals presume liberty to begin with; and further, there is assumed to be eternal moral law for which we should search and by which we should abide in our acts as free persons.
The Hope and the Hopelessness of Liberty
In closing, I would comment briefly about the hope of our cause the upholding of liberty.
If the end is embodied in the means, no libertarian can employ other than purely voluntary means to further the cause of liberty. This means education, persuasion, demonstration. In that way, others may be led to reform their conduct on behalf of liberty.
You cannot institutionalize liberty. You can only institutionalize its encroachments. Institutional devices for the purpose of protecting liberty always seem to have a way of enslaving its enslaving its presumed beneficiaries, sooner or later. Perhaps this is due to the fact that the core of liberty, and its hope, lies deep in the heart and soul of individual man something institutions can never have, something we cannot delegate to any institution.
Some believe the cause of liberty to be all but dead, a setting sun on the horizon of human affairs. To say that liberty is dead, however, is to say that human life no longer exists, for the urge to be free is embodied in the organism itself. If you repress liberty in one place, you are likely to stimulate it elsewhere, for man seems to will to be free however much he fumbles the means of its attainment.
I am reminded, when thinking of the socio-pathology of liberty, of some recent findings in medical pathology. James Reymers, in his experiments on germfree life, observes instances of how the total absence of germs transforms the host into a dangerously vulnerable form of life. In one instance, some germ-free chicks within 24 hours after being hatched all developed tremors and even death, whereas those chicks not germ-free suffered no such affliction. In another instance, the ovaries of females among a group of germ-free animals degenerated until reproduction stopped within the strain of the experiment. 
One cannot help but wonder if a similar benefit, somehow, may not arise out of attacks on liberty. Perhaps a u201Cgermfreeu201D (pure and unadulterated liberty) society, if we could attain it, might lack some sort of mysterious catalyst requisite to the survival of liberty. No one of us would, of course, destroy liberty with this purpose in mind. Others will surely take care of that task of destruction of liberty, and our help is not needed.
All history suggests, in any event, that complete and universal liberty is a star beyond our reach. Liberty ebbs and flows, never being fully gained and never being fully lost. Perhaps it is well that it is thus, for reasons we can only dimly perceive.
One bemoans, of course, all absence of liberty. In like manner he bemoans those unfulfilled desires which fuel the whole economic realm of affairs. Yet, if there were no economic goods or services in the world — if everything we desired were in plenitude — would that be a heaven or a hell? To what could we then aspire? For then living would be nothing but the sopping up of pointless pleasures in a livelihood barren of hope, lacking things hoped for and as yet unattained.
And so perhaps liberty apparently is a goal to be pursued but never fully captured in its purity. Such a thought may solace libertarians in their partial enslavement, living lonesomely among many enslavers. This concept gives hope and purpose to live by, provided one does not dash his hopes on some impossible goal. If instead he sets as his star the mere furtherance of liberty rather than its full attainment for the entire world, he need never lack hope and purpose in life. Merely to perfect his own conduct provides plenty of work for him to do — more than the best can attain in a lifetime.
 Free and Unequal: The Biological Basis of Individual Liberty (Austin, Texas: University of Texas Press, 1953); Biochemical Individuality: The Basis for the Genetotrophic Concept (New York: John Wiley & Sons, Inc., 1956).
 Two Roads to Truth: A Basis for Unity under the Great Tradition (New York: The Viking Press, 1953); The Biology of the Spirit (New York: The Viking Press, 1955).
 Numerous articles.
 Numerous articles, including his lecture at Massachusetts Institute of Technology, November 17, 1953, u201CPsychology, The Machine, and Society.u201D
 Human Destiny (New York: Longmans, Green & Co., 1947)
 See St. Matthew, 20:15
 James A. Reyniers, u201CThe Significance of Germ-free Life Methodology (Gnotobiotics) to Experimental Biology and Medicine,u201D MSC Veterinarian, Volume 13, No. 3, 1953, page 182.
December 8, 2005