19 On the evening of that day, the first day of the week, the doors being locked where the disciples were for fear of the Jews, Jesus came and stood among them and said to them, “Peace be with you.” 20 When he had said this, he showed them his hands and his side. Then the disciples were glad when they saw the Lord. 21 Jesus said to them again, “Peace be with you. As the Father has sent me, even so I am sending you.” 22 And when he had said this, he breathed on them and said to them, “Receive the Holy Spirit. 23 If you forgive the sins of any, they are forgiven them; if you withhold forgiveness from any, it is withheld.”
24 Now Thomas, one of the Twelve, called the Twin, was not with them when Jesus came. 25 So the other disciples told him, “We have seen the Lord.” But he said to them, “Unless I see in his hands the mark of the nails, and place my finger into the mark of the nails, and place my hand into his side, I will never believe.”
26 Eight days later, his disciples were inside again, and Thomas was with them. Although the doors were locked, Jesus came and stood among them and said, “Peace be with you.” 27 Then he said to Thomas, “Put your finger here, and see my hands; and put out your hand, and place it in my side. Do not disbelieve, but believe.” 28 Thomas answered him, “My Lord and my God!” 29 Jesus said to him, “Have you believed because you have seen me? Blessed are those who have not seen and yet have believed.”
30 Now Jesus did many other signs in the presence of the disciples, which are not written in this book; 31 but these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name.
In John 20:31 the gospel writer speaks directly to the reader, telling her that the primary purpose of John’s Gospel is to describe the signs or miracles worked by Jesus in order that readers come to believe Jesus is indeed the Messiah. All who hold this belief will obtain eternal life. The sense of believing intended by the gospel writer is not merely acknowledgement that a given proposition is true. Objective truths (facts, we can call them) are those propositions that can be demonstrated to be true according to evidence. A historian, for example, can find many facts in the New Testament. “Pontius Pilate was the Roman governor of Judea from 26–36 CE” is one such fact. Evidence for the truth or facticity of this proposition is provided by a combination of textual sources (references to Pilate in sources independent of the New Testament, such as Tacitus, Philo, and Josephus) and archeological artifacts (the so-called Pilate Stone, which was discovered in 1961). The act of believing, as intended by the writer of John, points to the trust and conviction that a proposition is true regardless of the evidence available either to support or to falsify the proposition.
The counterpoint to this notion of belief qua trust and conviction is provided by the story of the disciple Thomas. Thomas was not present when the resurrected Jesus appear to the other disciples. Despite their eyewitness testimony that the man they saw was really Jesus, Thomas declared that the only evidence he would accept was the empirical testimony of his eyes and hands. About a week or so later Jesus appeared again. He offered his hands and side for Thomas to inspect. Following Thomas’s moment of realization (“My Lord and my God!”), Jesus chided him for his reliance on evidence of any sort: “Have you believed because you have seen me? Blessed are those who have not seen and yet have come to believe” (20:29). One meaning of the Greek word πιστεύω (translated in the text as “come to believe”) is to hold a proposition to be true with trust and conviction. This proposition is not left vulnerable to doubt or skepticism—it is not treated as a belief at arm’s length, something that may or may not be true. According to the writer of John, the best and most commendatory form of believing is to accept as true the proposition “Jesus is the Messiah” with trust and conviction despite the absence of supporting evidence of any kind. Blessed are those, in other words, who believe despite the absence of empirical evidence.
The politics of belief relates to the task of distinguishing those beliefs which we rightfully hold in the absence of evidence and those beliefs for which we are obliged to wait for evidence. Generally speaking, this task consists of discerning the epistemic boundaries separating the domains of science and religion. In “The Will to Believe,” William James distinguishes the two domains in the following way. Science is concerned with objective facts. Judgment in scientific inquiries can be withheld—and in most, if not nearly all cases, ought to be withheld—until sufficient evidence has been gathered. Morality and religion, in contrast, focus on subjective values. By this James does not mean simply that values vary from one person to another. Rather, James’s insight is that in order to act with respect to moral or religious questions, one must hold one’s beliefs with conviction. For the purpose of action, it is not enough that one considers a belief to be possible. For a belief to motivate action, it must be grasped with trust and conviction.
Another difference between the two domains is that questions of morality and religion often demand action despite the absence of sufficient evidence. James calls these sorts of situations “forced options,” meaning that one has two real possibilities without the option to defer making a decisive choice. He condemns as a pernicious form of skepticism the attitude that one must strenuously withhold judgment in all cases—that is, to treat moral and religious questions the same as scientific ones. This is a kind of defective scientific inquiry that James derides as “scientific absolutism.” Scientific absolutists seek, consciously or not, to avoid errors in thinking rather than to seek the truth. To seek the truth with respect to moral and religious questions is to risk being wrong. But without taking this risk, some truths would simply not be realized.
Let’s take a mundane example. Consider Gene and Rita. Gene likes Rita. He likes her a lot. Gene wonders if Rita likes him. But he’s not sure. Gene has two options. Option one requires that Gene wait for sufficient evidence that Rita likes him before he acts. The risk incurred by Gene in waiting for sufficient evidence is that Rita will take his standoffish attitude as evidence that Gene does not like her. In that case there will never be evidence for Gene’s belief (“Rita likes me”). The second option is for Gene to act with trust and conviction that his belief (“Rita likes me”) is true. His experience will soon confirm whether this belief is true or not. James’s point is that Gene would never know whether his belief (“Rita likes me”) is true by treating it as a scientific hypothesis. In fact, if Gene discovers that Rita does indeed like him, he can be said to have created this truth by his action. The politics of belief points to Gene’s responsibility to discern that this is a forced option, which obliges him to act and not to wait for evidence to accumulate as if he were testing a scientific hypothesis.
I was reminded of this a couple of weeks ago when Ted Cruz, a Republican senator from Texas, announced his candidacy for President of the United States. In the days before and after the announcement there were several stories about Cruz in the Washington Post. Most of the stories contained standard fare: Cruz’s opposition to the Affordable Care Act (or “Obamacare”), his opposition to the Obama administration’s attempt to broker an agreement on nuclear weapons with Iran, his opposition to the Obama administration’s efforts to combat the Islamic State (or ISIS, or ISIL), his opposition—well, you get the picture. One item that caught my eye mentioned that Cruz “does not believe in climate change.” In an interview the day after his announcement, Cruz disparaged proponents of climate change as “global warming alarmists” who reject critics such as himself as “deniers” and “heretics.” The alarmists are the modern-day equivalent of the Flat Earth Society; the so-called deniers, in contrast, are the modern-day equivalent of Galileo.
According to Cruz, the debate over climate change is strictly ideological: on one side are the unreasonable “alarmists” who appeal to the authority of science without engaging the practice of science; on the other side are those reasonable persons who confront the evidence but are derided as “denialists” for their efforts. This is nothing more than what logicians call a false dilemma, a choice between two options in which the rejection of one option necessarily obliges the acceptance of the other. In the case of climate change, Cruz rejects credulity and embraces skepticism. But this isn’t the way science works. Scientists evaluate the probability of scientific hypotheses in light of the available evidence. The evidence determines whether a given hypothesis is more or less probable and thus capable of being known. Galileo, for instance, did not reject the Church’s position on the skeptical grounds that human beings could not know whether the Earth is the center of the universe; rather, he rejected geocentrism because heliocentrism (the view that the Earth and planets revolve around the Sun) was a better theory. Heliocentrism seemed more probable to Galileo because it better explained the available evidence.
The politics of belief points to a way of seeking truth as well as to the obstacles opposing such a quest. Fundamental to this search is the recognition and maintenance of the epistemic domains of science and religion. If science is allowed to dominate religion, we fall into what James describes as scientific absolutism. Doubting Thomas is one literary example of a scientific absolutist. If religion is allowed to dominate science, we succumb to a kind of defective fideism in which inward conviction is the dominant form of acceptable evidence. In practice this defective form of fideism functions as sophism, or the dark art of making bad arguments persuasive. Whenever ways of seeking religious truth are misused, the quest for truth in both science and religion suffers. Every time a politician or a religious leader describes a personal lack of belief in an issue such as climate change, evolution, or the advisability of childhood vaccines, we should take a stance of critical attentiveness. It makes little difference if the peddlers of sophistic eyewash are sincere or ravenous. We are wise to be equally wary of both.
 Zezima, Katie and Robert Costa, “It’s official: Cruz announces 2016 candidacy,” Washington Post, 23 March 2015.
 Sakuma, Amanda, “Ted Cruz: Climate change believers are the new ‘flat-Earthers’,” msnbc.com, 25 March 2015.