The major question that Falsification Principle poses to religious language can be found in the closing line of a lecture entitled Theology and Falsification, given by Anthony Flew in 1955, in which he says ‘I therefore put to the succeeding symposiasts the simple central questions, “What would have to occur or to have occurred to constitute for you a disproof of the love of, or of the existence of, God?”’ The central argument of Flew in his principle is that religious statements are not falsifiable, and are consequently meaningless. R.M. Hare and Basil Mitchell, among others, famously criticised the principle in the University Debate, Hare arguing that although religious language is non-cognitive it can still be meaningful, and Mitchell arguing that religious language is cognitive and therefore meaningful. Both, however, provide flawed arguments for why religious language must be meaningful. Consequently, Falsification Principle succeeds in reducing religious statements and language to something that it is meaningless.
Karl Popper originally posed a challenge to the Verification Principle, arguing that science must, in order to make progress, falsify hypotheses as opposed to verifying them. He believed that a hypothesis can never conclusively be verified and so the important thing to be determined was whether or not it could be falsified. Here arises the first strength of falsification when rendering religious language meaningless. Popper called the issue of distinguishing between cognitive, scientific statements and other statements, such as religious language, the ‘problem of demarcation.’ Popper claimed that for a statement to be ranked as scientific, it must be ‘capable of conflicting with possible, or conceivable, observations.’ This creates a flaw in religious statements because if the statements are scientific, for example ‘God loves me’ then it must be possible that the religious claims could conflict with sense observations and thus be undermined.
Anthony Flew, however, was influenced by Popper’s work to the point where he put forward a transmutation of the Verification Principle, known as the Falsification Principle. Flew believed, like the logical positivists, that propositions are only meaningful if they are factually significant. However his beliefs differed in that he applied Popper’s principle of falsification as the criterion of meaning. Flew used John Wisdom’s Parable of the Gardener written in 1944 to illustrate his belief that religious language is meaningless. In the parable an explorer maintains the existence of a gardener despite numerous pieces of evidence that display his non-existence, leading a second explorer to question ‘But what of your original assertion? Just how does what you call an invisible, intangible, eternally illusive gardener differ from an imaginary gardener or no gardener at all?’ Flew claims that the explorer begins with the assertion ‘a gardener exists’ but is then ‘reduced step by step to an altogether different status.’ Flew applies this analogy to religious people’s use of language about the existence of God. He claims that a religious believer begins with the assertion ‘God exists’, but when faced with the problem of evil, the assertion ‘dies the death of a thousand qualifications’ as they continuously attempt to qualify their initial statement in order to avoid admitting flaws. Here arises a strength of the Falsification Principle. Flew focuses specifically on the problem and existence of moral and natural evil, which provides a fundamental problem for religious believers for God’s existence, commonly known as the inconsistent triad. It is implausible for God to be omnipotent and omnibenevolent, and yet for evil to exist. Religious believers may respond to this but they ultimately fall victim to the ‘thousand qualifications’ that Flew proposed. For example, a religious believer may justify evil by