751. It is faith only in the last sense that is known as the theological virtue of faith, and hence with it alone we are here concerned. St. Paul describes this faith as follows: “Faith is the substance of things to be hoped for, the evidence of things that appear not” (Heb., xi. 1). This verse is variously interpreted. (a) According to St. Chrysostom, the meaning is: Faith is the subsistence or anticipated existence in the soul of future blessings that are hoped for, through the firm confidence it gives; it is the conviction of the reality of the unseen. (b) According to St. Thomas, the meaning is: Faith is the substance or basis on which is built the hope of blessedness, or on which rests as on its foundation the whole work of justification; it is an argument producing certainty of that which is not seen. The elements of St. Thomas’ interpretation have been incorporated into the Vatican Council’s definition: “The Catholic Church professes that this faith which is the beginning of human salvation is a supernatural virtue by which we, with the aid and inspiration of the grace of God, believe that the things revealed by Him are true, not because the intrinsic truth of these things has been perceived by the natural light of reason, but because of the authority of God Himself revealing, who can neither deceive nor be deceived” (Sess. 3, chap. 3, Denz. 1789). 752. Thus, faith is an intellectual habit and act, but it differs from all other intellectual habits and acts as follows: (a) it differs from science, vision, understanding, for its object is “the things that appear not”; (b) it differs from opinion, doubt, suspicion, for it is a firm “substance,” a certain “evidence”; (c) it differs from human faith or belief resting on man’s word and promises, for it is the pledge, beginning and cornerstone of the happiness promised by God Himself. 753. Faith will now be considered according to two aspects: (a) objectively, as regards the things that are believed by him who has faith; (b) subjectively, as regards the habit and act of the believer which put him in contact with these truths of the unseen world. 754. The Object of Faith.--There is a twofold object of faith, viz., material and formal. (a) The material object, or the truth that is believed, includes all that is contained in the Word of God, whether written or handed down by tradition. The principal material object is God Himself as the Deity, or Supreme Truth in Being (_prima veritas in essendo_); the secondary material object embraces all other revealed truths. (b) The formal object of faith, or the motive that prompts one to give assent to the material object, is the authority of God, who is Supreme Truth in Knowing and Speaking (_prima veritas in cognoscendo et dicendo_), and hence He can neither be deceived nor deceive.