the physical world? Can physical truth be in 

 opposition to moral truth? If certain men 

 cry out at the clanger with which a real disco- 

 very threatens an established doctrine, they 

 render this doctrine singularly suspicious; for 

 either it is false, or we may justly accuse the 

 weakness and ignorance of the pretended inter- 

 preters of God's works. 



Nothing can resist the power of truth. Now 

 if the truth remains, and public writers or even 

 governments attach to it pernicious consequences, 

 who does the mischief? On the other hand, is 

 it not at once impious and absurd to maintain 

 that laws and constitutions ought to be founded 

 on imposition, in order to insure the happiness 

 and tranquillity of men ? 



"Let us respect truth," you will tell me; 

 " but how are we to know that your doctrine of 

 the functions of the brain is the truth?" Truth, 

 as well as falsehood, has its proper physiognomy. 

 This doctrine owes its birth to incontestible 

 facts; these facts have revealed the general laws, 

 in virtue of which they take place ; they have 

 led to principles which prove themselves, in- 

 dependently of the facts from which they are 

 deduced : each new fact, whether furnished by 

 chance, or called forth by a mind eager for ex- 

 periment, becomes a new confirmation of it : 

 this doctrine has introduced clearness, confidence, 

 harmony and stability, where before there 

 reigned only obscurity, vacillation, contradiction, 

 versatility; it explains moral phenomena, and 

 the modifications of these phenomena at dif- 

 ferent ages and in the two sexes, in different 

 states of health and disease, and in different 

 nations. In man and in animals, it reveals to us 

 the secret of the diversity of instincts, propen- 

 sities, faculties as well in species as in indi- 

 viduals: from the polypus toman, it demonstrates 

 to us from fragment to fragment, the material 

 causes of the gradual perfection of their intel- 

 ligence, of which, descending in the opposite 

 direction from man to the polypus, and returning 

 piece by piece, it produces the diminution and 

 the degradation; the numerous propositions of 

 this doctrine, destroying the most accredited 

 errors, naturally sustain and strengthen each 

 other: it is eminently fruitful in application to 

 human affairs, to education, to the arts and 

 sciences, to the study of history, to medicine, to 

 philosophy, morals, criminal legislation, &c: 

 it opens to the observing naturalist a boundless 

 field for meditation. If these are the charac- 

 teristics of the truth and utility of a doctrine, 

 I am certain that we shall be more and more 

 struck with the truth and utility of the physiology 

 of the brain, in proportion as it is submitted to 

 more rigorous and multiplied tests. 



-Strongly impressed with these ideas and sup- 

 ported by these motives, I turned all my 

 attention to the finding of the means which, in 

 the least possible time, would enable me to 

 accumulate the greatest number of facts. I shall 

 speak of these means, when I treat of the pro- 

 pensities and faculties, and their organs, parti- 

 cularly. I will here give a single one, which 

 presented itself when I least thought of it, and 

 which greatly contributed to perfect my works. 



The first day of the year 1805, my father, 

 who resided at Tiefenbrunn, in the Grand Duchy 



of Eaden, wrote me these words ; " It is late, 

 and night cannot be far distant; shall I see you 

 once more?" Nothing but such an invitation, 

 joined to the ardent desire which I cherished in 

 my bosom of again seeing my beloved parents, 

 after an absence of twenty-five years, could have 

 induced me to leave my friends and my patients, 

 for a few months. I wished too, to avail myself 

 of this opportunity to communicate my disco- 

 veries to the learned men in the north of 

 Germany. That my interview with them might 

 not terminate in propositions and discussions 

 without proof, I took with me a part of my 

 collection. I was always convinced that, without 

 these visible and palpable proofs, it would never 

 be possible to fight victoriously against so many 

 preconceptions, prejudices, and contrary opi- 

 nions, as I must necessarily meet. 



I experienced, everywhere, the most flattering 

 reception. Sovereigns, ministers, philosophers, 

 administrators, artists, seconded my design on 

 all occasions, augmenting my collection, and 

 furnishing me everywhere with new observa- 

 tions. The circumstances were too favorable 

 to permit me to resist the invitations which 

 came to me from most of the universities. By 

 this means, my journey was lengthened far 

 beyond the term which I had first fixed; but 

 there likewise resulted so many discussions of 

 my doctrine, public and private, that it arrived 

 at a degree of maturity which few founders of 

 new doctrines have been able to attain during 

 their lives. 



This journey afforded me the opportunity of 

 studying the organisation of a great number of 

 men of eminent talents, and others of very 

 limited capacity, and I had the advantage of 

 observing the difference between them. I 

 gathered innumerable facts in the schools, and in 

 the great establishments of education, in the 

 asylums for orphans and foundlings, in the 

 insane hospitals, in houses of correction and 

 prisons, in judicial interrogatories, and even in 

 places of execution: the multiplied researches 

 on suicides, idiots, and madmen, have contri- 

 buted greatly to correct and confirm my opi- 

 nions. I have laid under contribution several 

 anatomical and physiological cabinets; I have 

 submitted antique statues and busts to my ex- 

 aminations, and have compared with them the 

 records of history. 



After having used, for more than thirty years, 

 such diversified means, I no longer feared the 

 danger or the reproach of having precipitated the 

 publication of my great work. I had more 

 reason to apprehend, that the great number of 

 proofs I had furnished in support of each of my 

 propositions, instead of being satisfactory, would 

 prove to the great body of my readers actually 

 alarming. As this first volume will be particu- 

 larly devoted to the exposition of the moral part 

 of the physiology of the brain, the reader may ask, 

 if a physician has the right to apply his know- 

 ledge to the study of morals, the improvement 

 of education, the houses of correction, of prisons, 

 of the penal code, of malefactors, &c. No one 

 disputes, that all institutions and all laws ought 

 to have for their basis the nature of man and the 

 wants of society. Now, to whom does human 

 nature reveal itself more openly, and with less 



