need not attempt to inquire； but the relatively high development of mathematics in the early historical period suggests that primeval man had attained a not inconsiderable knowledge of numbers。 The humdrum vocation of looking after a numerous progeny must have taught the mother the rudiments of addition and subtraction； and the elements of multiplication and division are implied in the capacity to carry on even the rudest form of barter； such as the various tribes must have practised from an early day。 As to political ideas； even the crudest tribal life was based on certain conceptions of ownership； at least of tribal ownership； and the application of the principle of likeness and difference to which we have already referred。 Each tribe； of course； differed in some regard from other tribes； and the recognition of these differences implied in itself a political classification。 A certain tribe took possession of a particular hunting… ground； which became； for the time being； its home； and over which it came to exercise certain rights。 An invasion of this territory by another tribe might lead to war； and the banding together of the members of the tribe to repel the invader implied both a recognition of communal unity and a species of prejudice in favor of that community that constituted a primitive patriotism。 But this unity of action in opposing another tribe would not prevent a certain rivalry of interest between the members of the same tribe； which would show itself more and more prominently as the tribe increased in size。 The association of two or more persons implies； always； the ascendency of some and the subordination of others。 Leadership and subordination are necessary correlatives of difference of physical and mental endowment； and rivalry between leaders would inevitably lead to the formation of primitive political parties。 With the ultimate success and ascendency of one leader； who secures either absolute power or power modified in accordance with the advice of subordinate leaders； we have the germs of an elaborate political systeman embryo science of government。 Meanwhile； the very existence of such a community implies the recognition on the part of its members of certain individual rights； the recognition of which is essential to communal harmony。 The right of individual ownership of the various articles and implements of every…day life must be recognized； or all harmony would be at an end。 Certain rules of justice primitive lawsmust； by common consent； give protection to the weakest members of the community。 Here are the rudiments of a system of ethics。 It may seem anomalous to speak of this primitive morality； this early recognition of the principles of right and wrong； as having any relation to science。 Yet； rightly considered； there is no incongruity in such a citation。 There cannot well be a doubt that the adoption of those broad principles of right and wrong which underlie the entire structure of modern civilization was due to scientific induction；in other words； to the belief； based on observation and experience； that the principles implied were essential to communal progress。 He who has scanned the pageant of history knows how often these principles seem to be absent in the intercourse of men and nations。 Yet the ideal is always there as a standard by which all deeds are judged。
It would appear； then； that the entire superstructure of later science had its foundation in the knowledge and practice of prehistoric man。 The civilization of the historical period could not have advanced as it has had there not been countless generations of culture back of it。 The new principles of science could not have been evolved had there not been great basal principles which ages of unconscious experiment had impressed upon the mind of our race。 Due meed of praise must be given； then； to our primitive ancestor for his scientific accomplishments； but justice demands that we should look a little farther and consider the reverse side of the picture。 We have had to do； thus far； chiefly with the positive side of accomplishment。 We have pointed out what our primitive ancestor knew； intimating； perhaps； the limitations of his knowledge； but we have had little to say of one all…important feature of his scientific theorizing。 The feature in question is based on the highly scientific desire and propensity to find explanations for the phenomena of nature。 Without such desire no progress could be made。 It is； as we have seen； the generalizing from experience that constitutes real scientific progress； and yet； just as most other good things can be overdone； this scientific propensity may be carried to a disastrous excess。 Primeval man did not escape this danger。 He observed； he reasoned； he found explanations； but he did not always discriminate as to the logicality of his reasonings。 He failed to recognize the limitations of his knowledge。 The observed uniformity in the sequence of certain events impressed on his mind the idea of cause and effect。 Proximate causes known； he sought remoter causes； childlike； his inquiring mind was always asking； Why？ and； childlike； he demanded an explicit answer。 If the forces of nature seemed to combat him； if wind and rain opposed his progress and thunder and lightning seemed to menace his existence； he was led irrevocably to think of those human foes who warred with him； and to see； back of the warfare of the elements； an inscrutable malevolent intelligence which took this method to express its displeasure。 But every other line of scientific observation leads equally； following back a sequence of events； to seemingly causeless beginnings。 Modern science can explain the lightning； as it can explain a great number of the mysteries which the primeval intelligence could not penetrate。 But the primordial man could not wait for the revelations of scientific investigation： he must vault at once to a final solution of all scientific problems。 He found his solution by peopling the world with invisible forces； anthropomorphic in their conception； like himself in their thought and action； differing only in the limitations of their powers。 His own dream existence gave him seeming proof of the existence of an alter ego； a spiritual portion of himself that could dissever itself from his body and wander at will； his scientific inductions seemed to tell him of a world of invisible beings； capable of influencing him for good or ill。 From the scientific exercise of his faculties he evolved the all…encompassing generalizations of invisible and all…powerful causes back of the phenomena of nature。 These generalizations； early developed and seemingly supported by the observations of countless generations； came to be among the most firmly established scientific inductions of our primeval ancestor。 They obtained a hold upon the mentality of our race that led subsequent generations to think of them； sometimes to speak of them； as 〃innate〃 ideas。 The observations upon which they were based are now； for the most part； susceptible of other interpretations； but the old interpretations have precedent and prejudice back of them； and they represent ideas that are more difficult than almost any others to eradicate。 Always； and everywhere； superstitions based upon unwarranted early scientific deductions have been the most implacable foes to the progress of science。 Men have built systems of philosophy around their conception of anthropomorphic deities； they have linked to these systems of philosophy the allied conception of the immutability of man's spirit； and they have asked that scientific progress should stop short at the brink of these systems of philosophy and accept their dictates as final。 Yet there is not to…day in existence； and there never has been； one jot of scientific evidence for the existence of these intangible anthropomorphic powers back of nature that is not susceptible of scientific challenge and of more logical interpretation。 In despite of which the superstitious beliefs are still as firmly fixed in the minds of a large majority of our race as they were in the mind of our prehistoric ancestor。 The fact of this baleful heritage must not be forgotten in estimating the debt of gratitude which historic man owes to his barbaric predecessor。
II。 EGYPTIAN SCIENCE In the previous chapter we have purposely refrained from referring to any particular tribe or race of historical man。 Now； however； we are at the beginnings of national existence； and we have to consider the accomplishments of an individual race； or rather； perhaps； of two or more races that occupied successively the same geographical territory。 But even now our studies must for a time remain very general； we shall see little or nothing of the deeds of individual scientists in the course of our study of Egyptian culture。 We are still； it must be understood； at the beginnings of history； indeed； we must first bridge over the gap from the prehistoric before we may find ourselves fairly on the line of march of historical science。 At the very outset we may well ask what constitutes the distinction between prehistoric and historic epochs a distinction which has been constantly implied in much that we have said。 The reply savors somewhat of vagueness。 It is a distinction having to do； not so much with facts of human progress as with our interpretation of these facts。 When we speak of the dawn of history we must not be understood to imply that； at the period in question； there was any sudden change in the intellectual status of the human race or in the status of any individual tribe or nation of men。 What we mean is that modern knowledge has penetrated the mists of the past for the period we term historical with something more of clearness and precision than it has been able to bring to bear upon yet earlier periods。 New accessions of knowledge may thus shift from time to time the bounds of the so…called historical period。 The clearest illustration of this is furnished by our interpretation of Egyptian history。 Until recently the biblical records of the Hebrew captivity or service； together with the similar account of Josephus； furnished about all that was known of Egyptian history even of so comparatively recent a time as that of Ramses II。 （fifteenth century B。C。）； and from t