'1st. That the progress of mankind depends on the success with which the laws of phenomena are investigated, and on the extent to which a knowledge of those laws is diffused. 2d. That before such investigation can begin, a spirit of scepticism must arise, which, at first aiding the investigation, is afterward aided by it. 3d. That the discoveries thus made increase the influence of intellectual truths, and diminish, relatively, not absolutely, the influence of moral truths; moral truths being more stationary than intellectual truths, and receiving fewer additions. 4th. That the great enemy of this movement, and therefore the great enemy of civilization, is the protective spirit—the notion that society cannot prosper, unless the affairs of life are watched over and protected at nearly every turn by the state and the church; the state teaching men what they are to do, and the church teaching them what they are to believe.'
In all these points the recent work of Professor Draper coincides with that of the lamented English writer. The main object of the former is, however, to discuss a question more basic than those undertaken by the author of 'Civilization in England,' the consideration of which was by him formally declined: namely, the question of a predetermined order of development lying back of all physical and mental phenomena. The opening sentences of the American book will sufficiently indicate the purpose of its pages:
'I intend, in this work, to consider in what manner the advancement of Europe in civilization has taken place, to ascertain how far its progress has been fortuitous, and how far determined by primordial law.
'Does the procession of nations in time, like the erratic phantasm of a dream, go forward without reason or order? Or, is there a predetermined, a solemn march, in which all must join, ever moving, ever resistlessly advancing, encountering and enduring an inevitable succession of events?
'In a philosophical examination of the intellectual and political history of nations, an answer to these questions is to be found. * * * Man is the archetype of society. Individual development is the model of social progress.'
It will be sufficient for our present purpose to indicate the line of Dr. Draper's argument, in seeking for a solution to the problem of progress, and to sum up the conclusions to which he is ultimately led by his investigations.
In the intellectual infancy of a savage state, man regards all passing events as depending on the arbitrary volition of a superior but invisible power. The tendency is necessarily to superstition. After reason, aided by experience, has led him forth from these delusions as respects surrounding things, he still clings to his original ideas as respects objects far removed, believing the stars to be inhabited by mysterious powers, or to be such themselves. Gradually he emerges from star worship as he did from fetichism, still venerating and perhaps exalting into immortal gods the genii whom he once supposed to inhabit the stars, long after he has ascertained that the latter are without any perceptible influence on him.
He is exchanging, by ascending degrees, his primitive doctrine of arbitrary volition for the doctrine of law. As the fall of a stone, the flowing of a river, and the ordinary operations of nature familiar to him have been traced to physical causes, to like causes are at last traced the revolutions of the stars. In events and scenes continually increasing in greatness and grandeur, he is detecting the dominion of law. This perception is extended, until at last it embraces all natural events, until they are seen to be the consequences of physical conditions, and therefore the results of law.
'But if we admit that this is the case, from the mote that floats in the sunbeam to multiple stars revolving round each other, are we willing to carry our principles to their consequences, and recognize a like operation of law among living as among lifeless things, in the organic as well as the inorganic world? What testimony does physiology offer on this point?'
Physiology, in its progress, has passed through the same stages as physics. Living beings were once considered to be beyond the power of external influences, the various physiological functions being carried forward by a feigned immaterial principle, called the vital agent. But when it was discovered that the heart is constructed upon the recognized rules of hydraulics; the eye upon the most refined principles of optics; that the ear was furnished with the means of dealing with the three characteristics of sound—its tympanum for intensity, its cochlea for pitch, and its semicircular canals for quality; and that the air, brought into the great air passages, calling into play atmospheric pressure, was conveyed upon physical principles into the ultimate cells of the lungs, and thence to the blood; when these and very many other like facts were brought into prominence by modern research, it became necessary to admit that animated beings do not constitute the exception once supposed, and that organic operations are the result of physical agencies.
'If thus, in the recesses of the individual economy, these natural agents bear sway, must they not operate in the social economy too?
'Has the great, shadeless desert nothing to do with the habits of the nomade tribes who pitch their tents upon it—the fertile plain no connection with flocks and pastoral life—the mountain fastnesses with the courage that has so often defended them—the sea with habits of adventure? Indeed, do not all our expectations of the stability of social institutions rest upon our belief in the stability of surrounding physical conditions? From the time of Bodin, who nearly three hundred years ago published his work 'De Republica,' these principles have been well recognized: that the laws of nature cannot be subordinated to the will of man, and that government must be adapted to climate. It was these things which led to the conclusion that force is best resorted to for northern nations, reason for the middle, and superstition for the southern.'
The importance of physical agents and physical laws in the social as well as in the individual economy, is variously illustrated by Professor Draper, who points out the essential part they play in several departments of nature. To the merely mechanical inclination of the earth's axis of rotation toward the plane of her orbit of revolution around the sun, we owe the changing seasons and the method of life which is dependent on these. The alteration of that physical arrangement would involve a corresponding alteration in the whole life of the globe. So, again, the possibility of existence upon the earth, in any way, depends upon conditions altogether of a material kind. It is necessary that our planet should be at a definite mean distance from the source of light and heat, the sun; and that the form of her orbit should be almost a circle, since it is only within a narrow range of temperature, secured by these conditions, that life can be maintained.