We confess that it appears to us a very puzzling "problem" to find out how to answer the foregoing criticism, or the others from non-catholic periodicals which it has been our hap to fall in with. Not one of them has seriously controverted the main thesis of the book they profess to criticise, or to make any well-motived adjudication of the several portions of the argument by which the thesis is sustained. Some, like the one before us, attempt to set aside the whole question; others content themselves with a round assertion that the arguments are inconclusive; and the residue confine themselves to generalities; or, at most, to the criticism of some minor details. We should not think it worth while to trouble ourselves or our readers with a formal replication to such superficial critics, were it not for the opportunity which is afforded us of bringing into clearer light the total lack of all deep philosophy or theology in the non-catholic world, and the value of the Catholic philosophy which we are striving to bring before the minds of intelligent and sincere inquirers after truth. The criticisms begin with the title of the work. The critic of _The Independent_ objects to our calling old questions _problems of the age_. _The Southern Review_ coincides with him, and suggests that they should rather have been called "problems _of all ages;_" while another critic, in _The Evening Post_, gives his verdict that they are all to be classed as "problems of a bygone age." This last criticism is the only one founded upon a reason; and is, at the same time, a full justification of the appropriateness of the title before all those who still profess to believe in the revelation of God. The different classes of protesters against the teaching of the church have wearied themselves in vain in searching for a satisfactory solution of the problems of man's condition and destiny; either in some new rendering of divine revelation, or in some system of purely rational philosophy. The despair produced by their utter failure vents itself in the denial that these problems are real ones, capable of any solution at all, and in the attempt to relegate them finally into the region of the unknowable. This is a vain effort. They have forced themselves upon the attention of the human mind ever since the creation, and they will continue to do so, in spite of all efforts to exorcise them. The relations of man to his Creator, the reason of moral and physical evil, the bearing of the present life on the future, the significance of Christianity, and such like topics, can be regarded as obsolete questions only by a most unpardonable levity. The so-called Liberal Christian and the rationalist may in deed proffer the opinion that the solutions we have given are already antiquated. But, with all the hardihood which persons of this class possess in so remarkable a degree in claiming for themselves all the light, all the intelligence, all the spiritual