Published for the first time in 1981, Faith and Reason by R. Swinburne is the final act of a trilogy concerning the philosophical theology, or better the philosophy of theism. The fundamental issue on which the three volumes go round is the question: is there a God? The first volume, The Coherence of Theism of 1977, focused on the analysis of the evidence and the claims concerning the internal coherence of God’s existence. The Existence of God of 1979 inquired the consistency of the classical arguments pro/contra the existence of God. In this work Swinburne argued that, though isn’t possible to prove definitively that God is existing, it is temporaly possible to rely oneself upon the so-called principle of credulity, which affirms: «in the absence of special considerations what one seems to perceive is probably so […] how things seem to be is good grounds for a belief about how things are» (p. 254). In Faith and Reason of 1981 Swinburne extends his investigation to the comparison of several religious beliefs in the attempt to define, from a peculiar philosophical perspective and through the application of probability criteria (similarities/differences), the reliability that a religious belief can have.

   The first part of the volume (chapter 1, The Nature of Belief; chapter 2, Rational Belief; chapter 3, The Value of Rational Religious Belief) is presented as an analysis of those notions that on a rational base, and with arguments derived from evidence, lead someone to ask whether to practise religion and, in the case of a positive answer, which religion to join. Swinburne declares that in every religious belief there are reasons of rational order, for it is necessary for the believer to assume that the religion chosen is true. Likewise, besides rational persuasions, to take part in a religious custom means to believe in the religion agreed, i.e. in the case of theism, to believe in God. But what type of belief is required for practising a religion, and what type of belief would be more rational to embrace? Swinburne, that in particular allows for belief required by Christianity, answers to the question (chapter 4, The Nature of Faith) taking into consideration the points of view of Thomism (p. 138), Lutheranism (p. 142), pragmatism (p. 147) and Patristics (p. 153).

   In the second part Swinburne asks what are the elements that differentiate and connect the various religious experiences. He identifies three goals that a religious person should pursue (chapter 5, The Purpose of Religion): to worship and obey God or gods; to gain salvation for himself; to help others to attain their salvation. The first of these goals is sought only by those who accept the existence of God or gods, while as regards the others two you need to remark that different religions propose different formulations of salvation. Comparing different religiuos beliefs Swinburne asserts that you should practise that religion which goals are considered the best and which creed is true in a degree more probable than one proposed by another religions. But on what the possibility to operate a choice can be founded? In order to reach the three goals presented above, that concern pratical behave of the believer inside a community, would be logical to choose the religion that has the more solid and persuasive rational component (chapter 6, The Role of Creeds).

   Swinburne proposes a few functional criteria to set out the difference between religious beliefs and to establish their truth and reliability degree on a probabilistic base. Religious beliefs can be subjected to the reason’s screening that, also using the comparative method, values the commitment statute (demand/offer of a sense) available by a specific belief and his power to satisfy the believer’s requirements. Nevertheless the true belief, whether we are speaking about it, doesn’t think it can be fully convincing (Epilogue: Faith is Voluntary). Faith and Reason, that in comparison with previous volumes is more centered on Christianity problems, is a bridge between the philosophy of theism works and the successive ones on Christian doctrine (Revelation, 1991; The Christian God, 1994; The Resurrection of God Incarnate, 2003). In The Existence of God Swinburne declared that it is more likely that God exists than the contrary. In The Resurrection of God Incarnate this idea is made stronger by considering that, starting from assumption based on natural theology evidence that there is a God, it is highly probable that such a God is embodied in Christ. A middle position compared to two just shown can be found in Faith and Reson as an argument for the rationality of the believing in Christian God.

   The second edition of Faith and Reason (2005), though actually doesn’t diverge from the first, has been improved in order to be presented as an answer to two other works that, placing in dispute with Swinburne’s point of view, have revived lately the debate on the rational nature of belief (religious or not). We are refferring to Warranted Christian Belief (2000) by Alvin Plantinga and to a renewal of John Hick’s claim, as you can find it in An Interpretation of Religion (1989) as well as in few following papers. According to Plantinga the rationality, namely justification or warrant, of every belief, including the religion one, belongs to the nature of those processes that produce it. Against this externalist position Swinburne objects that the belief’s rationality is due both to the believer’s introspective ability, that’s his capacity to watch inside himself and examine its own belief, and to the believer’s other beliefs. According to Swinburne, only the rationality in an internalist sense can somehow be important to the believer's behaviour. Hick instead claims that the life customs established by the most important religions are built on the same beahaviours and moral values, since the beliefs of these religions, although are spreaded by different myths, are the expression of the same eternal truth. Swinburne replies maintaining that main religions do pursue different aims, and there are some aims more worthy to be achieved. We conclude by saying that Faith and Reason is a key text for the comprehension of the development of more than thirty-year Richard Swinburne’s thought, and a not to be set aside reading to get closer to some fundamental questions promoted in contemporary discussion on religion. Moreover, for exposing clarity and methodological rigour, it had the merit to be able to fascinate as well analytic philosophy and epistemology in general.