Blasphemy can be a valuable act of expression. It is misleading to try and conflate blasphemous statements with statements that lack intellectual merit, are bigoted or hateful. The proposition side attempt to exclude “decent and temperate” questioning of religious values from the scope of anti-blasphemy laws, but they fail to recognise that language is a broad, imprecise and malleable tool. Words that may be understood as temperate and even-handed by one speaker may deeply shock another. Even a simple and plainly stated denial of God’s existence was interpreted as tantamount to blasphemy by the early liberal philosopher John Locke. Locke saw acceptance of the core truths of the Christian bible as being a vital indicator of and individual’s trustworthiness and willingness to comply with social norms.  It is easy to envision scenarios in which adherents of certain religions may find any attempt to dispute the historical and philosophical foundations of their faith deeply offensive, no matter how calmly and respectfully the dissenting position is communicated. Discussions of natural selection have become one such battleground. Despite the measures taken by philosophers and scientists to highlight the compatibility between religious faith and scientifically informed ontologies, despite the measured and carefully regulated court cases that have been used to decide this issue, many Christians regard discussion and teaching of evolution as part of natural history threatening and offensive.  Even irreverent humour or mockery can sometimes be used to make valid and useful observations about the structure and values of religions. For example, the act of angering someone by ridiculing their deity, or the tenets of their faith, could make the point that a particular religion is closed-minded or too hidebound. Important aspects of our characters are revealed when we are invited to adopt aggressive or defensive attitudes. It is not for a government to decide whether blasphemous statements contribute to social discourse; it is up to the individuals engaged in that exchange. It is not acceptable, in the absence of an intention to expose a particular group of people to a real risk of physical harm, to allow debate and free speech to be curtailed by the use of legal force.  The meaning of words need not be plain and obvious, either. Implication and allusion play an important role in language. Implied meanings and innuendos have done much to complicate the legal processes used to protect individual reputations against slurs and falsehoods. In a criminal, rather than a civil context, similar principles are likely to make blasphemy prosecutions expensive, unwieldy and inconsistent.