That the same causes, acting under different conditions, produce different and even opposite effects, is a well-known scientific truth. The same heat of summer which causes our foods to decay, promotes the growth of plants in the soil; the same cold of winter which increases the pain of bronchial affections, and cuts short the lives of aged and infirm persons, acts as a stimulant and a source of pleasure to the young and healthy. We need not therefore be surprised, that the same physical conditions and principles of nature, act as causes or conditions both of what we term evil and what we term good. If, also the theory of relativity in physical and mental action is true, that change of impression is a necessary cause or condition of consciousness, and that previous experience of pain increases the perception of pleasure, we possess in that theory, as one of the general ideas of science, a partial basis of morality. All these remarks tend to shew, that in order to obtain a truly scientific view of the nature of man, and of man's position and duties in the Universe, we must avoid the errors caused by uncorrected consciousness.
Another great moral effect of the continual discovery of new truth in science, is the gradual production and diffusion of uniformity of belief, first amongst scientific men, and then amongst the mass of mankind. This uniformity of belief is a necessary result of the invariability of fact and law; it does not extend to scientific opinions, hypotheses or theories, because they are not necessarily facts, and may be
erroneous. A knowledge of science tends to remove differences of opinion between man and man, because it enables every honest examiner to obtain essentially similar results. Scientific research will gradually disclose what is true and what is untrue in doctrine and empirical rules; and what is true will be retained. A universal religion or a scientific philosophy which is composed of contradictory creeds cannot be wholly true. Science is gradually superseding unreasonable beliefs, and inaugurating a true universal gospel in which all men will eventually think alike in fundamental matters. The continued discovery of new truth must of necessity sooner or later lead mankind to the source of all truth and to universal satisfaction and happiness. It has been frequently stated that science is antagonistic to religion; it is evident however that as science is so conducive to morality, it cannot be opposed to true religion, but only to false or unfounded beliefs. Nothing shews more plainly a weakness of moral confidence and a deficiency of faith in an over-ruling power, than a fear that the pursuit of scientific truth will lead to results injurious to mankind. What we most need to fear is, not that our most cherished doctrinal beliefs may be proved to be mistakes, but that we through deficiency of knowledge may be led to do wrong.
There are plenty of questions, especially in matters of theory and doctrine in concrete subjects, which science cannot directly and absolutely decide either one way or the other, but respecting which, by the
aid of new knowledge and of inference based upon it, science gradually accumulates so large a preponderence of evidence as conclusively settles them to the conviction of every unprejudiced and reasonable person. Many of the most deeply interesting questions in mental science and morality are of this kind; and will probably be settled in this manner. It is well-known also to scientific men that the indirect conclusions of the intellect and reasoning power are often more certain than the direct evidence of the senses and consciousness; we are more certain for instance that the Earth is a sphere than that it is a plane, although the former conclusion is arrived at largely by inference, whilst the latter is the direct testimony of uneducated consciousness. Whilst our senses and consciousness inform us that the Earth is a fixed body, inference proves to us that it is rushing through space at an immense velocity. Sense and consciousness are not intellect, although they are often treated as such. Their functions are to perceive and observe, to act as witnesses, to supply evidence to the judgment, and not to usurp the reasoning power. Even the universal consciousness of all mankind is insufficient to overthrow the final decisions of the intellect, or to decide what is true or false, because the senses and consciousness cannot compare or infer. As it is the force and repitition, and not the truthfulness of mental impressions, which largely determines belief, we are capable of believing error as well as truth, and we believe much that is erroneous until the
corrections of the intellect are applied to the evidence of the senses and feelings. The correctness or otherwise of our present beliefs will be tested in the future as others have been in the past, and the new experiences requisite for the purpose will probably be obtained by means of original research. It is a great mistake to suppose that the warrantable inferences deduced from scientific knowledge will not sooner or later profoundly influence questions relating to the highest hopes and aspirations of the human race, such as the independent existence and immortality of the human soul; that of a personal Ruler of the Universe; freedom of the will; the origin of evil; future reward and punishment; &c. By extension of knowledge a scientific system of morality will be formed. The great principles which govern the phenomena of all bodies are gradually being discovered, and when found we deductively apply them to ourselves, and thus arrive at a knowledge of our true position in nature, our duties, our proper course of conduct, &c. Science also by disclosing to us the true relations of matter to mind in the human brain, will probably not only make known to us the true limits of our mental powers and of the knowable, but also help to solve the problems of the relations of the Universe and of Man to an intelligent Creator. It will decide such questions, largely by shewing us whether or not the ideas we entertain respecting them are consistent with the more extensive knowledge evolved by research. A part of the data from which we may
safely predict that science will in the future exercise so great a moral influence over mankind, is the fact that its chief principles are fundamental guides and regulators of human action.
Probably nothing has a greater effect in making a man humble and reverent than a thorough knowledge of science. By the inventions of the telescope, microscope, spectroscope, telegraph, microphone, telephone, &c., the extremely finite extent of all our faculties has been abundantly demonstrated. Whilst the wonders of the telescope have developed an intelligent sentiment of reverence, by revealing to us a portion of the vast amount of the Universe of matter and energy, those of the microscope have strengthened that sentiment by affording us an insight into the almost endless complexity of minute creatures, substances and actions. Whilst also these and other scientific instruments and appliances have proved the excessively limited extent of our senses; the inscrutable character and immense number and variety of problems of nature yet unsolved, equally demonstrate the extreme feebleness of our mental powers. To obtain an accurate acquaintance with science also, and especially to discover new scientific truths, it is absolutely necessary to set aside human pride, and approach the subject like a little child; no other course is possible.
A knowledge of geology and astronomy also makes a man humble and reverent. The fact that this globe must have existed myriads of years; and is always moving at the immense velocity of more than 62,000
miles an hour in its orbit, is sufficient to convince any unprejudiced person of his own transient physical existence and his comparative physical feebleness and insignificance. Hitherto, man has largely been accustomed, through the influence of uncorrected impressions and other causes, to view all nature as having been expressly provided for him, but science informs us that whilst this Earth is suitable for his abode, and Nature ministers to his necessities and pleasures, it is only on condition that he first obeys the great laws of matter and energy, and adapts himself to their requirements. The operation of those laws often ruthlessly destroys thousands of men by pestilence, famine, drought, and other great calamities, and man can do nothing which is incompatible with them without suffering a penalty. Science shews that man is but one out of at least 320,000 different species of animals; it also discloses the fact that the entire human population of this globe constitute only about one 50,575,785 millionth part of the Earth, and proves to us that the Earth itself is but a speck in the Universe, one out of at least 75 millions of worlds; and that not only is it merely a planet revolving round the Sun, but that the Sun is only one of a multitude of Suns, and is itself, with all its planets, revolving round a still more distant centre in space.