Johnny Depp remains a big name at the box office. Whenever his name is attached to a project, it can be guaranteed that people will turn out. While that usually means buying a ticket at the box office for his latest movie, the organisers of a 'Reason Rally' are hoping he'll prove just as popular at their event.

This week Depp, along with the likes of Richard Dawkins, was announced as one of the speakers at this year's rally. Dawkins, along with Lawrence Krauss, are typical of the event's speakers – they're well-known scientific and educationalist figures who say they're 'free thinkers' or 'rationalists.'

This is where we hit a problem. Many of the Reason Rally's aims seem laudable. In a pluralist, free society, statements like "Democracy works best when everyone's voice is heard" should be welcomed. A vibrant democracy needs a wide variety of voices. The issue with the rally isn't that it wants a plurality of voices in public debate – the problem is that it seems to be claiming 'reason' and even 'rationality' solely for the atheist camp.

This is a major overreach on the part of the atheist community and it doesn't stand up to scrutiny.

Reason is a good thing, as is rationality. We should all have reasons for the faith (or lack of) that we proclaim. 1 Peter 3:15 tells us as much. Atheists, humanists, secularists and others are happy to do the same of course – to give a reason for their ideological and metaphysical commitments.

Atheism isn't, though, the default, or only 'reasonable' position.

Similarly with rationalism. It's vital that we rationally engage with our faith. St Paul demonstrated his willingness to argue for his beliefs, not just from the perspective of the revelation given to him, but on a rational basis as well.

He debated with the Stoic and Epicurian philosophers in Athens, as recounted in Acts 17. Similarly today many Christians, atheists and those of other persuasions are happy to engage in debate for the rational basis for their commitments.

Again, this is fine. But there is overreach if atheists claim that their worldview is the only one with a rational basis. Christian (and other theist) philosophers have been debating the rational basis for faith in God for thousands of years. There are some aspects of atheism that cannot be said to be 'more rational' than an orthodox Christian viewpoint.

Take Lawrence Krauss for instance. In his book, A Universe From Nothing Krauss claims, "The metaphysical 'rule'... that 'out of nothing nothing comes,' has no foundation in science... All it represents is an unwillingness to recognize the simple fact that nature may be cleverer than philosophers or theologians."

Notice the two ways in which Krauss tries to martial 'rationality' to his cause here. He suggests that the only way to ascertain if something is true is via science. Then he claims that nature is cleverer than those he disagrees with. It's pretty thin gruel really, as an argument. Yet his huge book sales imply many agree with him.

Thank goodness then for those who point out the gaping chasms in the argument that to be atheist is the only way to be rational. One of them is David Bentley Hart. The Orthodox philosopher argues, "Those who most like to flatter themselves that they are the austerest of rationalists (that is, atheists, materialists, metaphysical naturalists... that crowd) would find the notion that reason arises from an irreducibly fiduciary movement of the will risible, even perhaps sordid... The unyielding rationalist turns out to be the most irrational fideist of all: one who believes in reason even though there cannot possibly be any reason for that belief."

Faith commitments should be held up to scrutiny and argument. But claims of atheists and materialists, be it Dawkins or Depp, must be held up to the same level of scrutiny.

Three cheers then, for reason and rationality. But beware before claiming all reason and rationality under the sun for your side of the argument.