UNBELIEF. — The term used in theology to denote the absence or rejection of the supernatural virtue of faith; it is therefore a form of infidelity. If the lack of faith stems from absolute impossibility or from invincible ignorance, there arises what is improperly called negative unbelief, which is also referred to as such. This is found, for example, in children before Baptism and in adult pagans to whom the Gospel has not yet been preached. This unbelief is involuntary and therefore free from any guilt (Rom 10:14). For this reason, Pius V on 1 October 1567 condemned the following proposition of Baius: “Purely negative unbelief is a sin in those to whom Christ has not been preached” (Denz-U, 1068).
On the contrary, properly so-called unbelief, or positive unbelief, since it arises from voluntary ignorance or the conscious denial of faith, is gravely culpable (cf. John 15:22; Rom 11:20; 2 Thess 1:8-10). Here we are concerned only with positive unbelief, which can manifest itself in various ways:
a) First, by the voluntary denial of the motives of credibility, a denial which, by suppressing the preambles of faith, renders belief impossible. Therefore, whoever professes atheism is an unbeliever, for by denying the existence of the witness who is God, he removes every foundation from faith. The same must be said of the conscious denial or positive doubt regarding the fact of Revelation.
b) Unbelief also arises from the rejection of the formal and specific motive of every act of faith, namely, the authority of God, the right of the divine witness to be believed when He attests a truth or a dogma. Consequently, whoever would deny or positively doubt the existence of God or His veracity would place himself in a condition in which he could not believe, for he would be denying or doubting the truth of His testimony.
c) Unbelief can also result from the denial or positive doubt regarding the material object of faith. Considered from this aspect, unbelief is complete if it involves the denial of the entire content of Christian Revelation, as occurs in the faithful who abandon the Church to adhere to a false religion, for example, to skepticism; it is partial if it implies the rejection of some or even a single revealed truth, as happens in the believer who renounces the Catholic faith to give his allegiance to an erroneous choice, for example, to Calvinism.
d) Finally, unbelief is perfected by impugning the very norm of belief, which is the authority of the ecclesiastical magisterium: the conscious and persistent refusal to submit to its infallible definitions in matters of faith constitutes the sin of heresy.
Unbelief is generally considered by theologians to be the gravest sin after formal hatred of God. For sin consists essentially in turning away from God, and therefore it will be all the more grave the more it separates one from God. Now unbelief turns away from God to the greatest possible extent (cf. Summa Theologiae, II-II, q. 10, art. 1, 3), especially because, by rejecting faith, it destroys the principle of salvation, the foundation and root of justification (cf. Denz-U, 80). The malice of unbelief can vary according to the different aspects under which it is considered. Thus, with regard to its extension, that is, the number of truths denied or the errors professed, the unbelief of the pagan is greater (more extensive) than that of the Jew, and the unbelief of the Jew greater than that of the heretic. On the other hand, with regard to intensity, that is, the voluntary and deliberate resolve to renounce faith, the order is reversed. Indeed, in the pagan who has had no knowledge of the Gospel, or only insufficient and inexact knowledge, faith is simply absent: it is a deficiency, not a fault, and therefore his unbelief is purely negative.
In the Jew, however, it is positive, culpable, and therefore worse than the unbelief of the pagan, because the Jew knows the entire revelation of the Old Testament, which he has corrupted with his false interpretations. But far more grave is the unbelief of the heretic, who, by persistently repudiating divine dogma, comes to destroy the virtue of faith that already existed in his soul by virtue of the sacrament of Baptism. For this reason St. Thomas affirms that, considered in itself, “the unbelief of the heretic is the worst” (Summa Theologiae, II-II, q. 10, art. 3).
The ultimate reason for unbelief lies in the very nature of faith, which not only is a free act but is also difficult to perform, for it requires assent to truths for which no internal demonstration is given, an assent that is not merely theoretical but also practical, by which the whole person must be inwardly transformed so that faith may become the norm of life through the observance of precepts that are burdensome and repugnant to corrupted nature. It is clear, then, that faith cannot be unanimous, and that, consequently, the fact of unbelief arises from the resistances of pride (John 6:44), of disordered attachment to earthly goods (Eph 4:17; 1 Tim 6:10), of luxury, of avarice (Luke 16:27-31), and of other passions. Positive unbelief always has its cause in evil deeds (John 3:19), and for this reason the Vatican Council declared that a Catholic can never abandon his faith without sin (Denz-U, 1797).
Unbelief is not to be regarded as a rare, extraordinary phenomenon, but as a permanent, continuous fact that has always existed and is constantly renewed whenever God reveals Himself to man, whether directly or indirectly through others (Isa 53:1; Rom 10:16). Life and history are founded upon this great choice: God or not God, faith or unbelief. Until the end of the world, the preaching of the Gospel will always meet with the same result that attended the apostolate of St. Paul among the Jews living in Rome, of whom “some were convinced by what he said, while others refused to believe” (Acts 28:30). Nevertheless, although unbelief is a persistent fact mysteriously embedded in the life of humanity, it does not always present the same features: both in its causes and in its manifestations it is conditioned by the modalities of time and depends more or less on the vicissitudes of history. Thus, at the beginning of the evangelical preaching, alongside Judaism there emerged many other forms of unbelief, such as Gnosticism, Marcionism, Montanism, etc., which were followed by the Christological and Trinitarian heresies of the 4th, 5th, and 6th centuries. The Manichaean heresy spread widely; it was energetically opposed and routed by St. Augustine, only to reappear in a renewed and threatening form in the heresy of the Albigensians. Other heretical sects were added to those already mentioned in the succeeding centuries. But it was with the Protestant Reformation and especially with the Enlightenment of the 18th century that unbelief ceased to be partial and became complete, inasmuch as it was no longer limited to the rejection of one or some truths defined by the Church, but rejected the entire deposit of Revelation in its entirety and even denied the very possibility of the supernatural order. Thus there arose naturalism and rationalism, which in the 18th and 19th centuries came to concentrate exclusively on reason applied to the study of phenomena and their laws, that is, on science.
Among the principal forms of unbelief still alive and operative in the intellectual, moral, political, and social orders, there may be mentioned communism, the existentialism of Heidegger and Sartre, the idealism of G. Gentile and B. Croce, the pure rationalism of P. L. Couchoud, secularism, and indifferentism. Unbelief is also implicit in Modernism (Denz-U, 2109).
trad. it., Turin 1937; G. Baroni, È possibile perdere la fede senza peccato? Dottrina dei teologi dei secc. XVII-XVIII, Rome 1937; G. Combès, Le retour offensif du paganisme, Paris 1938; B. Guzzetti, La perdita della fede nei cattolici, Vicenza 1940; L. Febvre, Le problème de l’incroyance au XVIe siècle. La religion de Rabelais, Paris 1942; A. Dal Covolo, La psicologia dell’incendio alla luce del quarto Evangelio, Milan 1945; M. F. Sciacca, La filosofia oggi, Verona 1945; E. Borne, L’incroyance, in Apologétique, 2nd ed., Mainz 1948, pp. 352-73; M. J. Guitton, Difficultés à croire, Paris 1948. For a more extensive and complete bibliography of Borne, op. cit., p. 873.