There is nothing of more importance for anyone who wishes to secure his salvation, than to know himself that is to say, to know-at least as far as this is possible-in what state his conscience is. This knowledge is to be attained only by frequent and serious examen, and such examen is distinguished into different classes. 1st. The examen which all should make, when preparing for Confession. 2d. The daily examen which should be made every evening before going to bed, to discover the faults we may have been guilty of during the day, and to ask pardon for them. 3d. Finally the particular examen, so called because it limits itself to some particular fault we are anxious to eradicate, or some virtue that we wish to acquire. It is for the purpose of facilitating the practice of this last class of examens, that the subjects treated of in the present work have been arranged. To perform an exercise of so much importance with advantage, it is necessary to choose, with the advice of one's director, the subject on which we should wish to examine ourselves, for a certain number of days or weeks, or even for a longer time, if he should think it advisable. If the examen has for its object some fault we wish to correct, such fault should be our most habitual, our predominant sin, the one that causes those faults that lead us most frequently to the tribunal of penance, and the one that offers the greatest obstacle to our advancement in the way of perfection. If, on the other hand, the examen has for its end to acquire some virtue, it ought to be one of those virtues which are most necessary for us in the state we have embraced, and in the employment we follow; the virtue most painful and repugnant to nature, that, in fine, which helps us to advance in the way of salvation, and gives merit to the good works adapted to the profession in which we have been called to sanctify ourselves. This matter once settled, we must first choose a fixed and definite time each day for this exercise; second, we must read over by ourselves and with attention the subject we have selected; third, we must seriously question ourselves as to the conduct we have observed with regard to that particular fault or virtue since our last examen; and, fourth, we must make a firm resolution to labor at correcting that fault or practising that virtue, and to do so by the employment of means distinctly determined upon. It is not sufficient, however, to know our predominant sin, and reckon up and weigh the number of faults we may have committed under that head; we must also seek out what are the causes of our faults, that we may courageously assail them; without" which, we shall obtain no satisfactory results. A tile on the roof of the house gets out of place, and the water drops into the apartment; should we confine ourselves to drying the spot, we should have to renew our task every day; but if we go to the cause, and replace the tile, the water will soon cease to flow. "When a thorn has entered the hand, we must first of all extract it; without this, no remedies will be of any avail. It is so with our predominant sin; if the cause is not got rid of, the effects will always remain.