To sum up, the chief methodological principle which we have striven to keep always before us, is a thorough clearness about every step of our reasoning. In the first place, therefore, care has been taken to give an explicit and a perfectly clear survey of the statements; and to draw conclusions in such a way that all our reasons for drawing them shall be as clear as possible to the reader, so as to enable every one to apply his own criticism as easily as possible at any stage of our reasoning. Necessarily in a study such as the present one, some allowance must be made for a subjective element in the final judgments on the value of the evidence. But just as the writer must ask for a certain amount of trust in his scientific judgment, so he is bound to give every means to the reader to enable him always fully to judge and exercise his criticism on the use the author is making of this liberty. In order to achieve this as far as in us lies, the methodological principles set forth above have been adopted. They are in short, as follows: We accept as facts those points in which all statements agree. On controversial points we try to eliminate the contradictions by applying textual criticism to the statements, or by pointing out the possible sources of error, or by showing that these contradictions must be set down to local differences between the tribes. In drawing conclusions, we shall point out those facts which are well established, and also point out those which are more or less uncertain or contradictory. The sources used are not very numerous, but it is hoped that they will be found sufficient. They have been impartially chosen and include each of the various types of Australian evidence. CHAPTER II MODES OF OBTAINING WIVES Keeping to these general methodological principles, the aim of this study will be merely an objective, unprejudiced description of the different forms of the Australian family organization. In accordance with what has been said above, let us accept at the outset a general definition, along the lines of which our investigations will be carried out. My choice for this purpose is the well-known definition of Dr. Westermarck: "Marriage is a more or less durable connection between male and female, lasting beyond the mere act of propagation till after the birth of the offspring." In another place (_Moral Ideas_, ii. p. 364) Dr. Westermarck completes this definition: "As a social institution, on the other hand, it has a somewhat different meaning: it is a union regulated by custom and law. Society lays down the rules relating to the selection of partners, to the mode of contracting marriage, to its form, and to its duration." We may also remember that Dr. Westermarck first pointed out that "marriage is rooted in family, rather than family in marriage"[39]; and that he insists on the importance of economic elements in family life, and especially on the facts of the rearing of children and the mode of living.