“ Yet, unless it be thoroughly engrained in the mind, the whole economy of Nature, with every fact of distribution, rarity, abundance, extinction, and variation, will be dimly seen or quite misunderstood. We behold the face of Nature bright with gladness; we often see superabundance of food. We do not see, or we forget, that the birds which are idly singing round us mostly live on insects or seeds, and are thus constantly destroying life ”

“ Ought we to listen to the cry of humanity that life is too short, and that it will be well to prolong it? If the question were merely one of prolonging the life of old people, without modifying old age itself, the answer would be doubtful. It must be understood, however, that the prolongation of life will be associated with the preservation of intelligence and of the power to work. When we have reduced or abolished such causes of precocious senility as intemperance and disease, it will no longer be necessary to give pensions at the age of sixty or seventy years. ”

“ It is not less evident that intellectual life, or the powers of the understanding and the mind, make themselves most apparent in the circumference and form of the solid parts of the head, especially the forehead; though they will discover themselves to the attentive and accurate eye in every part and point of the human body, by the congeniality and harmony of the various parts. Is there any occasion to prove that the power of thinking resides not in the foot, nor in the hand, nor in the back, but in the head and its internal parts? ”

“ As natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection.
It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us. ”

“ It is indisputable that all men estimate all things whatever by their external temporary superficies—that is to say, by their physiognomy. Is not all nature physiognomy, superficies and contents, body and spirit, external effect and internal power? There is not a man who does not judge of all things that pass through his hands by their physiognomy—there is not a man who does not more or less, the first time he is in company with a stranger, observe, estimate, compare, judge him according to appearances. ”

“ Even accomplished scientists and philosophers have advanced impossible and contradictory theories.
All attempts at explanation have been stultified by an ignorance of the facts to be explained, or by a partial survey of them, and especially by a neglect of the evidence afforded by fossils. How was it possible not to perceive that the theory of the earth owes its origin to fossils alone? They alone, in truth, inform us with any certainty that the earth has not always had the same covering, since they certainly must have lived upon its surface before they were buried in its depths. ”

“ The relations of all animals and plants to each other in the struggle for existence are most complex, and often unexpected. Battle within battle must be continually recurring with varying success; and yet in the long run the forces are so nicely balanced that the face of Nature remains for long periods of time uniform, though assuredly the merest trifle would give the victory to one organic being over another. Nevertheless, so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being ”

“ If this something is the potential energy of the two particles, as in Neumann's theory, how are we to conceive this energy as existing in a point of space coinciding neither with the one particle nor with the other? In fact, whenever energy is transmitted from one body to another in time, there must be a medium or substance in which the energy exists after it leaves one body, and before it reaches the other, for energy, as Torricelli remarked, "is a quintessence of so subtile a nature that it cannot be contained in any vessel except the inmost substance of material things." ”

“ Morality should be based not on human nature in its existing condition, but on ideal human nature, as it may be in the future. Before all things, it is necessary to try to amend the evolution of human life, that is to say, to transform its disharmonies into harmonies. This task can be undertaken only by science, and to science the opportunity of accomplishing it must be given. Before it is possible to reach the goal mankind must be persuaded that science is all-powerful and that the deeply-rooted existing superstitions are pernicious. ”

“ The power of social opinion is apt to be underrated rather than overrated. Like the atmosphere which we breathe and in which we move, social opinion operates powerfully without our being conscious of its weight. ”

“ The improvement of instruments, and the continued enlargement of the field of observation, render investigations into natural phenomena and physical laws liable to become antiquated, to lose their interest, and to cease to be read.
Let none who are deeply penetrated with a true and genuine love of nature, and with a lively appreciation of the true charm and dignity of the study of her laws, ever view with discouragement or regret that which is connected with the enlargement of the boundaries of our knowledge. ”

“ How will the struggle for existence act in regard to variation? Can the principle of selection, which we have seen is so potent in the hands of man, apply under Nature? I think we shall see that it can act most efficiently. Let the endless number of slight variations and individual differences occurring in our domestic productions, and, in a lesser degree, in those under Nature, be borne in mind, as well as the strength of the hereditary tendency. Under domestication, it may be truly said that the whole organisation becomes in some degree plastic. ”

“ It is clearly seen that there is such a close affinity, such an identity in all essential points, in our corporeal structure, and in many of our instincts and passions with those of the lower animals—that man is so completely subjected to the same general laws of reproduction, increase, growth, disease, and death—that if progressive development, spontaneous variation, and natural selection have for millions of years directed the changes of the rest of the organic world, we cannot expect to find that the human race has been exempted from the same continuous process of evolution. ”

“ Is not the goal of existence the accomplishment of a complete and physiological cycle in which occurs a normal old age, ending in the loss of the instinct of life and the appearance of the instinct of death? But before attaining the normal end, coming after the appearance of the instinct of death, a normal life must be lived; a life filled all through with the feeling that comes from the accomplishment of function. Science has been able to tell us that man, the descendant of animals, has good and evil qualities in his nature, and that his life is made unhappy by the evil qualities. ”

“ We thus see that the building up of the human body from a single cell is a substantial epitome of the long story of evolution, which occupied many millions of years. We find man bearing in his body to-day traces of organs which were useful to a remote ancestor, but of no advantage, and often a source of mischief to himself. We learn that the origin of man, instead of being placed a few thousand years ago, must be traced back to the point where, hundreds of thousands of years ago, he diverged from his ape-cousins, though he retains to-day the plainest traces of that relationship. ”

“ HOW much may the anatomist see in the mere skull of man! How much more the physiognomist! And how much more still the anatomist who is a physiognomist! If shown the bald head of Cæsar, as painted by Rubens or Titian or Michael Angelo, what man would fail to notice the rocky capacity which characterises it, and to realise that more ardour and energy must be expected than from a smooth, round, flat head? ”

“ The ideas have long held my fancy that we men may be the chief, and perhaps the only executives on earth; that we are detached on active service with, it may be only illusory, powers of free-will. Also that we are in some way accountable for our success or failure to further certain obscure ends, to be guessed as best we can; that though our instructions are obscure they are sufficiently clear to justify our interference with the pitiless course of Nature whenever it seems possible to attain the goal towards which it moves by gentler and kindlier ways. ”

“ Everywhere the order of things changes so gradually that man cannot observe the change directly, and the animal tribes in every place preserve their habits for a long time; whence arises the apparent constancy of what we call species—a constancy which has given birth in us to the idea that these races are as old as nature.
But the surface of the habitable globe varies in nature, situation, and climate, in every variety of degrees. The naturalist will perceive that just in proportion as the environment is notably changed will the species change their characters. ”

“ Just as we must study the nature of plants before trying to realise our ideal, so also varied and profound knowledge is the first requisite for the ideal of moral conduct. It is necessary not only to know the structure and functions of the human organism, but to have exact ideas on human life as it is in society. Scientific knowledge is so indispensable for moral conduct that ignorance must be placed among the most immoral acts. A mother who rears her child in defiance of good hygiene, from want of knowledge, is acting immorally towards her offspring, notwithstanding her feeling of sympathy. ”

“ The activity of the mind exerts itself on the elements furnished to it by the perceptions of the senses. Thus, in the youth of nations there manifests itself in the simplest intuition of natural facts, in the first efforts made to comprehend them, the germ of the philosophy of nature.
If the study of physical phenomena be regarded in its bearings not on the material wants of man, but on his general intellectual progress, its highest result is found in the knowledge of those mutual relations which link together the general forces of nature. ”

“ Without fertility in the earth, many races of plants and animals would soon perish, or be extinct; and with permanency in our land it were impossible for the various tribes of plants and animals to be dispersed over the surface of a changing earth. The fact is that fertility, adequate to the various ends in view, is found in all the quarters of the world, or in every country of the earth; and the permanency of our land is such as to make it appear unalterable to mankind in general and even to impose upon men of science, who have endeavoured to persuade us that this earth is not to change. ”

“ The carbon of the food, not meeting with a sufficient supply of oxygen to consume it, passes into other compounds containing a large excess of carbon—or, in other words, fat is produced. Fat is thus an abnormal production, resulting from a disproportion of carbon in the food to that of the oxygen respired by the lungs or absorbed by the skin. Wild animals in a state of nature do not contain fat. The production of fat is always a consequence of a deficient supply of oxygen, for oxygen is absolutely indispensable for the dissipation of excess of carbon in the food. ”

“ The laws governing inheritance are for the most part unknown. No one can say why the same peculiarity in different individuals of the same species, or in different species, is sometimes inherited and sometimes not so; why the child often reverts in certain characters to its grandfather or grandmother, or more remote ancestor; why a peculiarity is often transmitted from one sex to both sexes, or to one sex alone, more commonly but not exclusively to the like sex.
The fact of heredity being given, we have evidence derived from human practice as to the influence of selection. ”

“ Purely passive, or what may be styled mechanical evolution displays the awe-inspiring spectacle of a vast eddy of organic turmoil, originating we know not how, and travelling we know not whither. It forms a continuous whole, but it is moulded by blind and wasteful processes—namely, by an extravagant production of raw material and the ruthless rejection of all that is superfluous, through the blundering steps of trial and error. ”

“ This empiricism—melancholy inheritance of earlier times—invariably maintains whatever axioms it has laid down; it is arrogant, as is everything that is narrow-minded; while true physical philosophy, founded on science, doubts because it seeks to investigate thoroughly—distinguishes between that which is certain and that which is simply probable—and labours incessantly to bring its theories nearer to perfection by extending the circle of observation. ”

“ The Creator, then, is seen to have formed our earth, and effected upon it a long and complicated series of changes, in the same manner in which we find that he conducts the affairs of Nature before our living eyes; that is, in the manner of natural law. This is no rash or unauthorised affirmation. It is what we deduce from the calculation of a Newton and a Laplace on the one hand, and from the industrious observation of facts by a Murchison and a Lyell on the other. It is a point of stupendous importance in human knowledge ”

“ For instance, if a seed of some meadow flower is carried to dry and stony ground, where it is exposed to the winds and there germinates, the consequence will be that the plant and its immediate offspring, being always ill-nourished, will give rise to a race really different from that which lives in the field; yet this, none the less, will be its progenitor. The individuals of this race will be dwarfed; and their organs, some being increased at the expense of the rest, will show distinctive proportions. What nature does in a long time we do every day ourselves. ”

“ Everything, therefore, concurs to prove my assertion, to wit—that it is not form, whether of the body or of the parts, which gives rise to the habits of animals and their manner of life; but that, on the contrary, in the habits, the manner of living, and all the other circumstances of environment, we have those things which in the course of time have built up animal bodies with all their members. With new forms new faculties have been acquired, and little by little nature has come to shape animals and all living things in their present forms. ”

“ The chemical energy represented by the satisfaction of the chemical affinities of a grain of water and four grains of zinc can evolve electricity equal in quantity to that of a powerful thunderstorm. Nor is it merely true that the quantity is active; it can be directed—made to perform its full equivalent duty. Is there not, then, great reason to believe that, by a closer investigation of the development and action of this subtile agent, we shall be able to increase the power of our batteries, or to invent new instruments which shall a thousandfold surpass in energy those we at present possess? ”

“ Science is mind applied to nature. The external world only exists for us so far as we conceive it within ourselves, and as it shapes itself within us into the form of [Pg 159] a contemplation of nature. As intelligence and language, thought and the signs of thought, are united by secret and indissoluble links, so, and almost without our being conscious of it, the external world and our ideas and feelings melt into each other. "External phenomena are translated," as Hegel expresses it in his "Philosophy of History," "in our internal representation of them." ”

“ Why have not the bowels of the earth preserved the monuments of so remarkable a genealogy unless it be that the species of former ages were as constant as our own, or at least because the catastrophe that destroyed them had not left them time to give evidence of the changes? ”

“ In every one of us there is a living process of combustion going on very similar to that of a candle. For it is not merely true in a poetical sense—the relation of the life of man to a taper. A candle will burn some four, five, six, or seven hours. What, then, must be the daily amount of carbon going up into the air in the way of carbonic acid? What a quantity of carbon must go from each of us in respiration! A man in twenty-four hours converts as much as seven ounces of carbon into carbonic acid ”