Santiago Ramón y Cajal
Rules and Advice on Scientific Investigation

Chapter II
Daunting worries of the novice

Excessive admiration. Exhaustion of scientific issues. Exclusive worship of applied science. Alleged shortness of vision.

(a) Excessive admiration for the work of the great pioneers

mong the most disastrous worries of the intellectual youth we count the ex­treme ad­mi­ra­tion for the work of the great ta­lents and the con­vic­tion that, given our li­mi­ted powers of ima­gi­na­tion, we will not be able to do any­thing to con­tinue or complete it.

This excessive devotion to genius is rooted in a double sentiment of fairness and mo­des­ty, too agreeable to be con­demn­able; but, if it do­mi­na­tes the novice's mind too much, it annihilates all initiative and makes him totally incapable of ori­gi­nal re­search. A de­fect for a de­fect, ar­ro­gance is pre­fer­able to ti­mi­di­ty: bold­ness sizes up its forces and wins or is defeated; but excessive modesty flees from the battle and condemns itself to shameful inaction.

When we abandon that atmosphere of ex­cel­lence that one breathes when read­ing the book of a bril­liant re­sear­cher, and we go to the laboratory to confirm the facts on which he bases his fascinating ideas, it sometimes happens that our worship of the idol diminishes as much as the feeling of our own esteem grows. Great men are, at times, geniuses, at times, children, and always unfinished. Even granting that the genius, subjected to the contrast of observation, comes out pure of all error, let us consider that all that he has discovered in a given domain is almost nothing in comparison with what he leaves to be discovered.

Nature provides us all with an in­ex­haust­ible wealth, and we have no reason to envy those who preceded us, nor to ex­claim like Alexander before the victories of Philip: "My father will leave me nothing to conquer".

It is not fair to ignore that there are scientific creations so complete, so bril­liant and so solid, that they seem to be the fruit of an almost divine intuition, having emerged perfect, like Minerva from the head of Jupiter. But the just ad­mi­ra­tion caused by such works would be greatly di­mi­ni­shed if we were to imagine the time and effort, the patience and per­se­ve­rance, the trials and cor­rect­ions, even the co­in­ci­den­ces that col­la­bo­ra­ted in the final success, to which they contributed almost as much as the genius of the scien­tist. It is the same as the marvelous adap­ta­tions of the organism to certain func­tions. The eye or the ear of the ver­te­bra­te, exa­mined in isolation, are astonishing, and it seems impossible that they could have been formed by the sole intervention of natural laws; but if we consider all the grades and forms of transition that these organs offer us in the phylogenic series, from the sketchy ocular outline of certain infusoria and worms to the complicated organization of the eye of the lower ver­te­brate, our amazement is hardly di­mi­ni­shed, and our mind becomes more and more inclined to the idea of a natural for­ma­tion by means of variations, organic cor­re­la­tions, se­lec­tions [⇒1] and adap­ta­tions.

What a great stimulus it would be for the novice observer if his teacher, instead of astonishing and discouraging him with the sheer excellence of the great finished projects, were to explain to him the genesis of each scientific achievement, the series of errors and hesitations that preceded it, which constitute, from the human point of view, the true explanation of each discovery! Such a skillful pe­da­go­gi­cal tac­tic would give us the con­viction that the discoverer, while being an en­light­en­ed genius and a powerful mind, was, after all, a man like any other.

Far from being disheartened by the great authorities of Science, the no­vice re­sear­cher should know that his destiny, by a harsh but inescapable law, is to grow a little at the expense of their prestige. Few will be those who, having started their scientific explorations with some good luck, have not been obliged to break and some­what di­mi­nish the pedestal of some historical or contemporary idol. As classi­cal ex­amp­les, let us remember Galileo refuting Aristotle in regard to gravitation; Co­per­ni­cus ruining Ptolemy's system of the world; Lavoisier reducing to nothing Stahl's conception of phlogistics; Virchow refuting the spontaneous generation of cells, hypothesized by Schwann, Schleiden and Robin. This law is so general and com­pell­ing that it is found in all domains of science and reaches even the humblest scientists. If we could not even name our­selves after having cited such high ex­amp­les, we would add that, when we began our researches in the ana­tomy and phy­sio­logy of the nervous centers, the first obstacle we had to remove was the false theory of Gerlach and Golgi on the diffuse nervous networks of the gray matter and on the mode of trans­mission of the currents.

In the life of wise men there are, as a rule, two phases: the creative or initial one, devoted to eliminate the errors of the past and to the discovery of new truths, and the mature or reasoning phase (which does not necessarily coincide with old age), during which, with the de­creas­ing en­er­gy of scien­ti­fic pro­duc­tion, the hypo­the­ses con­ceiv­ed in the youth are defended [⇒2], protecting them with pa­ter­nal love from the attack of the new­comers. As history goes on, there is no great man who is not fond of his titles and who does not fiercely dispute with the new generation his rights to glory. Very sad, but very true, is often that bitter phrase of Rousseau: "There is no wise man who does not prefer the lie invented by him to the truth discovered by another".

Even in the most exact sciences one never fails to find some credo ex­clu­si­ve­ly main­tained by the principle of authority. To de­mons­trate the fallacy of this con­cep­tion and, if possible, to refute it with new research, will always constitute an ex­cel­lent way of in­au­gu­rat­ing one's own scien­ti­fic work. It matters little if the amend­ment is re­ceiv­ed with mal­evo­lent cen­sures, with perfidious insults, with even meaner silence; given that right is on his side, the young innovator will not take long in dragging along the youth, which has no past to defend; all impartial scholars will also be at his side who, amidst the over­whelm­ing torrent of the reigning doctrine, knew how to keep their spirits sober and their judgment independent.

However, it is not enough to demolish: it is necessary to build. Scientific criticism is justified only by delivering, in exchange for an error, a truth. Usually, the new doctrine will emerge from the ruins of the abandoned one, and will be based strictly on facts correctly interpreted. It will be the innovator's duty to exclude any pious concession to traditional error or to fallen ideas, if he does not want to see his fame soon shared by the meticulous and per­fect­ing spi­rits that sprout in great num­bers, following each discovery, like mush­rooms under the shade of a tree.

(b) Belief in the exhaustion of scientific issues

Here is another of the false concepts often heard from our new graduates: "Everything substantial in every scientific subject is ex­haust­ed; what does it matter that I can add some detail, glean in a field where more diligent observers have gathered co­pious harvest? Because of my work, nei­ther Science will change its aspect, nor my name will come out of obscurity".

This is how laziness often sounds, disguised as modesty. This is how some young people of talent speak when they are shocked by the prospects of the great task at hand. There is no other choice but to radically eradicate such a shallow concept of Science, if the young researcher does not want to succumb definitively to the struggle that is waged in his will between the utilitarian suggestions of the moral environment, aimed at turning him into a common and moneyed amateur, and the noble impulses of duty and patriotism that drag him to honor and glory.

In his desire to satisfy the honorable obligation to his teachers, the novice observer would like to find a new vein on the surface of the earth, whose easy exploitation would raise his name; but, unfortunately, as soon as the first literature explorations are undertaken, he recognizes with pain that the vein lies at great depth and that the superficial deposit has been almost exhausted by fortunate observers who arrived before him, and who exercised the comfortable right of first explorers.

The people who think this way do not even realize that if we have arrived late for some questions, we were born too early for others, and that, after a century, we will come to be, by the force of things, the possessors of science, who removed its withered flowers and exploited the smallest details.

It is not right, however, to ignore that there are epochs in which, from a coincidentally discovered fact or the creation of a successful method, great scientific progress is made in succession, as if by spontaneous generation. This happened during the Renaissance, when Descartes, Pascal, Galileo, Bacon, Bayle, Newton, our Sanchez, etc., revealed the errors of the ancestors and generalized the belief that, far from the Greeks having exhausted the domain of science, they had only taken the first steps in the positive understanding of the Universe [⇒3]. For a scientist it is fortunate and great to be born in one of these great moments of ideas, during which, having made a clean slate of much of the work of the past, nothing is easier than to choose a fruitful subject.

But let us not exaggerate this consideration, and let us keep in mind that, even in our time, scientific progress is often built on the ruins of theories that were considered indestructible. Let us consider that, if there are sciences that seem to be on the verge of perfection, there are others in the process of being established and some that have not yet been born. In biology, especially, despite the immense work carried out in the last century, the most essential questions still await solution (origin of life, problem of heredity and evolution, structure and chemical composition of the cell, etc.).

In general, it can be said that there are no exhausted questions, but men exhausted in the questions. Once the ground is depleted for a wise man, it proves fertile for another. A fresh talent, coming without prejudice to the analysis of a subject, will always find a new aspect, something that was not noticed by those who thought that particular study to be definitively exhausted.

So fragmentary is our knowledge that even in the most meticulously explored subjects, at times unusual discoveries may emerge. Who, a few years ago, would have suspected that light and heat still held secrets for science! And yet there is the argon of the atmosphere, the x-rays of Röntgen and the radium of the Curie couple, to show how insufficient are our methods and how premature our conclusions.

In the field of biology we find the best application of Saint-Hilaire's beautiful phrase: "Infinity is always in front of us". And Carnoy's no less graphic thought: "Science can be created, but will never be created". It is not given to all to venture into the jungle and to trace, by sheer energy, a practicable path; but even the humblest of us can take advantage of the path opened by the genius, and tear, walking along it, some secret of the unknown.

While accepting that the beginner must settle for picking up details that escape the attention of the initiators, it is also true that those who search for small details end up acquiring such exquisite analytical sensitivity and such remarkable observational skills that they are finally successful in tackling crucial issues.

How many facts, apparently trivial, have led certain researchers, adequately prepared by the knowledge of methods, to great scientific conquests! Let us consider, moreover, that, as a consequence of the progressive diversification of science, the trivial things of today will perhaps be important truths tomorrow.

Not to mention that our appreciation of the important and the accessory, the great and the small, is based on a false judgment, on a true anthropomorphic error. In Nature there are neither superior nor inferior, nor accessory and principal things. These hierarchies which our spirit takes pleasure in assigning to natural phenomena, come from the fact that, instead of considering things in themselves and in their internal concatenation, we look at them only in relation to the utility or pleasure they can give us. In the chain of life all the links are equally valuable, because they are all equally necessary. We judge as small what we see from afar or do not know how to see. Even if we adopt the point of view of human egocentricity, how many questions of high humanity are latent in the mysterious protoplasm of the humblest microbe! Nothing seems more far-reaching in bacteriology than the knowledge of infectious bacteria, and nothing more secondary than that of the harmless microbes swarming in infusions and decaying organic matter; and yet, if these humble microbes, whose mission is to integrate back into the general circulation of matter the principles sequestered by the higher animals and plants, were to disappear, the planet would soon become uninhabitable for man.

Perhaps in no domain is the importance of detail better shown than in the technical methods of biology. To cite but one example, let us remember that R. Koch, the great German bacteriologist, by having had the idea of adding to a basic aniline color a little alkali, succeeded in staining and discovering the tuberculosis bacillus, thus unraveling the etiology of a disease hitherto rebellious to the astuteness of the most distinguished pathologists.

When it comes to the appraisal of scientific findings, this lack of rational perspective has been the fault of even the most brilliant geniuses.

What germs of great inventions, mentioned as curiosities of minor importance, we find today in the works of the ancients and even in those of the wise men of the Renaissance! Lost in an indigestible Treatise on Theology (Christianismi Restitutio), Servetus wrote, as if in disdain, three lines on the pulmonary circulation, which today constitute his principal mark of glory. Great would be the surprise of the philosopher from Aragon if today he were to be resurrected and see his laborious metaphysical discourses totally forgotten, and a fact glorified to which he must have given no more interest than that of an ancillary argument for his thesis that the soul resides in the blood! From a passage of Seneca it is inferred that the ancients already knew the amplifying power of a crystal sphere filled with water. Who would have suspected that in such an amplifying phenomenon, neglected for centuries, slept in germ two powerful analytical instruments: the microscope and the telescope, and two sciences, each one more grandiose than the other: Astronomy and Biology!

In short, there are no small matters; those that appear as such are large matters that are not understood. Instead of trivialities unworthy of being considered by the thinker, what we have are men whose intellectual smallness does not reach to penetrate the importance of the insignificance. Nature constitutes a harmonious mechanism, in which all the parts, even those that seem to play an accessory role, conspire in the functional whole; in contemplating this mechanism, the superficial man arbitrarily distinguishes its principal organs into essential and secondary; on the other hand, the discriminating thinker is content to rank them, disregarding size and their immediate useful effects, into known and little-known. As to their future significance, no one can be a prophet.

(c) Exclusive worship of the practical (applied) science

Another mistake in reasoning that must be fought at all costs is the fallacious separation of theoretical and practical (applied) science, with the consequent praise of the latter and the systematic disregard of the former. This error is unconsciously propagated among the youth, distracting them from any work of selfless research.

It is certainly not the people in the trade who show such a lack of assessment, but many lawyers, writers, industrialists and, unfortunately, even some well-known statesmen, whose decisions can have such serious consequences for the development of the national culture.

The following sentences do not just slip from their lips: "Less doctors and more industrialists. Nations do not measure their greatness by what they know, but by the amount of scientific discoveries applied to commerce, industry, agriculture, medicine and the military arts. Let us leave the cunning and smooth-tongued German Jews with their subtle inquiries of pure science, with their mad eagerness to scrutinize the last springs of life, and let us devote ourselves on our part to extract the practical juice from the principles of Science, turning them into positive improvements of human existence. Spain needs machines for our trains and ships, practical recipes for agriculture and industry, fertilizer factories, efficient hygiene; in short, everything that contributes to promote the population, wealth and welfare of the people. God save us from idle wise men, engaged in idle speculations, or given over to the pursuit of what is too little, which, if it were not too expensive, could be called a frivolous and even preposterous pastime."

Such is the accumulation of ignorance expressed at every step by those who, when traveling abroad, see by a mysterious mirage progress in the effects and not in the causes; those who, in their limited vision, do not perceive those mysterious threads that link the factory to the laboratory, like the stream to its spring. They believe in good faith that both wise men and peoples form two groups: those who waste their time in speculations of pure and sterile science, and those who know how to find facts of immediate application to the increase and comfort of life [⇒4].

Need we insist on the absurdity of such a doctrine? Is there anyone so lacking in common sense that he does not realize that where principles or facts are discovered, applications also spring up immediately? In Germany, in France, in England, the factory lives in close contact with the laboratory, and usually the originator of the scientific discovery himself directs, either on his own or through exploiting companies, the industrial use. Such alliances are evident in those great factories of aniline colors, which constitute one of the most prosperous branches of German, Swiss and French industry. So well known is this fact, that illustrative examples need not be given here. However, because they are recent and significant, I would like to mention two of them: the great industry of the precision lense production (microscopic, photographic and astronomical) established in Germany from the profound studies of mathematical optics of Professor Abbe, of Jena, and which assure to Prussia a monopoly of enormous value that covers the whole world [⇒5], and the manufacture of therapeutic sera, originating in Berlin and perfected in Paris, in which Behring and Roux, creators of the scientific principles of serotherapy, are involved, as it is only natural and justified.

Let us cultivate science for its own sake, without considering for the moment its applications. They always come; sometimes they take years, sometimes centuries. It matters little whether a scientific truth will be used by our children or by our grandchildren. The cause of progress would have been in vain if Galvani, if Volta, if Faraday, if Hertz, discoverers of the fundamental facts of the science of electricity, had disregarded their findings because they lacked industrial application at that time.

We have stated earlier that the human point of view of uselessness, though accepted (with the necessary restrictions of time and place), does not exist in Nature. And, in the last analysis, even if it were not possible to use certain scientific achievements for our comfort and profit, there would always remain a positive utility: the noble satisfaction of our satisfied curiosity and the incomparable fruition caused in the spirit by the feeling of our power in the face of the difficulty overcome.

In short: when approaching a problem, let us consider it in itself, without getting sidetracked by ulterior motives, the pursuit of which, by dispersing our attention, would diminish our analytical strength. In the struggle with Nature, the biologist, like the astronomer, must disregard the ground he is inhabiting and concentrate his gaze on the serene region of ideas, where, sooner or later, the light of truth will emerge. Once the new fact is established, the applications will come at the right time, that is to say, when another fact capable of fertilizing it appears; for, as it is well known, invention is nothing other than the conjunction of two or more things in a useful outcome. Science records many facts whose usefulness is at present unknown; but, at the end of a few years or perhaps centuries, a new truth comes to light which has mysterious affinities with those facts, and the resulting industrial creature is called photography, phonograph, spectral analysis, wireless telegraphy, mechanical flight, etc.

It is always a short or long term synthesis. Porta discovered the camera obscura, an isolated fact, which was hardly used for the art of design; Wedgwood and Davy pointed out in 1802 the possibility of obtaining photographic images on a paper lubricated in a solution of silver nitrate; but as the copy could not be fixed, this other discovery had no consequences; then came John Herschel, who managed to dissolve the silver salt not impressed by the light; thus it was possible to fix the fugitive luminous silhouette. However, the weak sensitivity of the silver salts hitherto used made the use of Porta's apparatus almost impossible; finally came Daguerre, who in 1839, with the exquisite sensitivity of silver iodide, revealed the dormant image; he admirably combined the inventions of his predecessors and created the foundations of today's photography.

This is how all inventions evolve: the ingredients are, at different times, found by shrewd yet unfortunate observers who did not manage to gather any fruit from their findings, waiting for the fruitful truths; but once all the data is gathered, a wise man arrives, happy, not so much for his originality as for having been born at the right time; he considers the facts from the human point of view, carries out the synthesis and the invention takes shape.

(d) Alleged shortness of vision

To justify dropouts and withdrawals, some claim a lack of capacity for science. "I have a fondness of laboratory work," they tell us, "but I am not good at discovering anything." True, there are minds unwilling to engage in experimental work, and among them we count all those incapable of prolonged attention and devoid of curiosity and admiration for the works of Nature. However, are the vast majority of those who confess themselves incapable of it positively so? Do they not, perhaps, exaggerate the difficulties of the undertaking, and the scarcity of their aptitudes? We think so, and we will add that many usually take for incapacity the mere slowness of conceiving and learning, and, sometimes, laziness itself or the lack of some secondary quality, such as patience, thoroughness, constancy. These are attributes that can soon be acquired with the habit of work and with the satisfaction of success.

In our opinion, the list of those fit for scientific work is much longer than is generally believed, and is composed, not only of the superior talents, of the effortless, of the sharp minds, greedy for reputation and anxious to link their name to a great work, but also of those regular intellects, known by the term 'craftsmen', for the skill and dexterity with which they carry out all manual work; of those others endowed with an artistic temperament and who vehemently feel the beauty of the works of Nature; finally, of those who are merely curious, inquisitive, and cautious, devoted to the worship of the small, and capable of devoting long hours to the examination of the most insignificant natural phenomena. Science, like armies, needs generals and soldiers; the former conceive the plan, but the latter are the ones who positively win. The collaboration of the perfectionists and reaffirmers is not only modest, but also highly admirable: thanks to these workers of progress, the conception of a genius acquires vigor and clarity, passing from the category of abstract symbol to a living reality, appreciated and known to all.

In order for each one to ascertain his aptitude for laboratory work, various means can be tried. Referring here to the studies of our predilection, we would advise these two:

First, the use of an analytical method that passes as uncertain and difficult, until, by dint of patience and work, the results mentioned by the creators are obtained. Flattering success in this case, especially if it has been achieved without the supervision of the teacher, that is, working in isolation, will be a clear indication of aptitude for research work.

Secondly, the study of a scientific subject, of a certain difficulty, where contradictory opinions abound, and for which the amateur will prepare himself by superficially examining the state of the question (mere reading of reference books, without going to the special Monographs). If, after a few months of experimental work, our beginner notices, on consulting the most modern references on the subject, that he has managed to guess some recent conquests; that on highly disputed points he has coincided with the interpretations of illustrious scholars; that, finally, he has succeeded in avoiding errors of appreciation made by some authors. Then he should abandon his timidity and give himself unreservedly to scientific work, because in it, triumphs and satisfactions await him, few or many, depending on the activity he deploys.

Also the moderately gifted, from the intellectual point of view, will be able to achieve some fruit, as long as they have strong faith in the creative virtue of education and are committed to deepen, for a long time, a limited subject.

Even at the risk of becoming redundant or of appearing heavy and long-winded, allow us to present the following reflections against those who are skeptical about the wonders of the will:

(a) As many thinkers and educators have affirmed, discovery is not the fruit of any special original talent, but of common sense improved and strengthened by technical education and by the habit of meditating about scientific problems [⇒6]. Thus, whoever has a regular standard of judgment to guide him in life, will also have it to walk unhindered along the path of research.

(b) The juvenile brain possesses exquisite plasticity, whereby it can, at the impulse of an energetic desire, extraordinarily improve its organization, creating new parallels between ideas, refining and improving judgment.

(c) The deficiencies of the native aptitude can be compensated by an extra amount of work and attention. It could be said that work replaces talent or, rather, creates talent. Whoever strongly desires to improve his ability will eventually succeed, provided that the educational work does not begin too late, at a time when the plasticity of the nerve cells is almost completely suspended. Let us not forget that by reading and meditating on masterpieces, every man is able to assimilate a large part of the genius that created them, since he takes from it not only the teachings, but also the criteria, the guiding principles and even the style.

(d) In most cases, what we call genius and special talent does not imply qualitative superiority, but superiority in speed, consisting only in doing in a hurry and with brilliant success what regular intellects elaborate slowly, but well. Instead of differentiating the awareness into big and small, it would be preferable and more accurate (at least in many cases) to classify them into slow and fast [⇒7]. The rapid intellects are certainly the most brilliant and suggestive; they are irreplaceable in conversation, in public speaking, in journalism, in any work in which time is a decisive factor; but in scientific undertakings the slow ones are as useful as the rapid ones, because the scientist, like the artist, is not judged by the verve, but by the excellence of producing. We would still venture to add that, by a quite common compensation, slow heads possess great endurance for prolonged attention, and open wide and deep furrows in questions; while quick ones are apt to become fatigued soon after they have scarcely cleared the ground. There are, however, numerous exceptions to this: Newton, Davy, Pasteur, Virchow, etc., were fast talents and left a wide and luminous trail.

(e) If, in spite of the efforts made to improve it, our memory is fickle and not very persistent, let us manage it well. As Epictetus says: "When in the game of life bad cards are dealt, there is no choice but to make the best possible use of the ones we have". The history of great discoveries teaches us that their excellence does not always stem from a superior talent, but from regular, yet skillfully applied understanding and memory. Great scientific innovators, such as Helmholtz, complained of a shortage of memory, considering it an ordeal to learn a piece of writing by heart. On the other hand, those with a poor memory for words and phrases usually enjoy excellent retention of ideas and chains of reasoning. Locke already noted that those endowed with great wit and quick memory do not always excel in judgment.

(f) In order to devote all the limited faculties we possess to the subject of our reflections, let us discard unnecessary pursuits, and those stray ideas touching the petty details of life, and let us focus our minds only on the subject of the problem at hand, for the sake of a deep and persistent attention. Let us confine ourselves, during the gestation of our work, to ignoring everything else: politics, literature, music, gossip, etc. There are cases in which ignorance is a great virtue, almost a heroism: useless books, disturbers of attention, weigh and occupy a place in our brain as much as in the shelves of libraries, and undo or hinder the mental adaptation of the subject. Knowledge takes up space, whatever popular wisdom may say.

(g) Even the average talent will succeed in enlightening itself with valuable works in several sciences, provided it abandons the pretension of covering them all at once; it will therefore concentrate its attention successively, that is to say, by epochs, on each subject, and will weaken or erase its previous achievements in other domains. Which is equivalent to declaring that the brain is adaptable to total science in time, but not in space. In fact, even great capacities proceed in this way; and so, when some wise man astonishes us with publications on various disciplines, let us note that to each subject corresponds to an epoch. Certainly, the previous knowledge will not have entirely disappeared from the author's mind, but it will have been simplified, condensed into very abbreviated formulas or symbols; in this way, a large space may be left free on the cerebral blackboard for the registration and engraving of the new images. end-black


Translation: © 2022 by TRTF.

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Santiago Ramón y Cajal:
Reglas y Con­se­jos sobre In­vesti­ga­cion Cien­ti­fica.

6th edition. Madrid 1923.


Chapter II: Daunting worries of the novice

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Capítulo II: Pre­ocu­pacio­nes ener­va­do­ras del princi­pi­ante

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