leaves fixed, although he may not always keep it before him. . . . “It is in this humour, fluctuating and variable as it is, that he combats with an invincible firmness the heretics of his time, who assumed to know the exclusive sense of Scripture. From the same point of view he thunders vigorously against the horrible impiety of those who dare to be certain that there is no God! He attacks them especially in the ‘Apology for Raymond de Sebonde.’ Having voluntarily set aside revelation, and abandoned themselves to their natural light—all faith set aside—he asks them on what authority they, who know not the essential reality of anything, dare to judge of that Sovereign Being who is infinite by His very definition. He demands upon what principles they rest, and presses them to point them out. He examines all that they bring forward, and so searches them by his wonderful penetration as to show the hollowness of what passes for the most clear and established truths. He inquires if the soul knows anything whatever—if it knows itself; whether it is substance or accident, body or spirit; what is each of these things, and if there is anything belonging to some order different from either; if the soul knows its own body; if it knows what matter is, or can distinguish the innumerable varieties of body produced from matter; how it can reason if it is material, and how it can be united to a special body, and feel its passions if it be spiritual. When did it begin to be, with the body or before, and if it ends with it or not? . . . . The ideas of God and truth are inseparable, and if the one is or is not, if the one is certain or uncertain, the other is necessarily the same. Who knows if the common sense (_le sens commun_) which we take as a judge of the truth is really this, designed for such a purpose? Who knows what truth is, and how can we be sure of having it without knowing it? Who knows even what Being is, since it is impossible to define it; and in trying to do so, it is necessary to presuppose the very idea itself, and say _it is_? . . .