Before entering on an analysis of the general principles of the Game of Whist, it is advisable to explain shortly on what foundation these principles rest; for it might be supposed that a demonstration of the propositions contained in these pages is about to be offered; that the chances for and against all possible systems of play have been calculated; and that the one here upheld can be proved to be certainly right, and all others certainly wrong. Such a view would be altogether erroneous. The problem is far too intricate to admit of being treated with mathematical precision. The conclusion that the chances are in favour of a certain line of play is not arrived at by abstract calculation, but by general reasoning, confirmed by the accumulated experience of practised players. The student must not, therefore, expect absolute proof. He must frequently be satisfied if the reasons given appear weighty in themselves, and none weightier can be suggested on the other side; and also with the assurance that the method of play recommended in this work is for the most part that which, having stood the test of time, is generally adopted.