This is my first issue as editor. So perhaps it's not surprising that I've spent a good deal of time recently pondering and puzzling over what may appear to be a fairly fundamental question: what, actually is humanism? I suspect that even those of you who have been readers for a long time – the magazine is 120 years old this year – have asked yourself the same question from time to time. In my first few weeks I brushed up on the history of rationalist free-thinking and secular humanism, starting with the illustrious A team: Thomas Hardy, Robert Owen, Bertrand Russell, HG Wells, EM Forster, Mary Wollstonecraft, Sartre. All of these are inspiring but there were no great surprises.

It was only when I dug a little deeper that I started to stumble on some less expected champions of humanism. Here was the powerful tradition of Afro-diasporic humanist thought – sociologist WEB Dubois, Harlem renaissance figures Langston Hughes and Zora Neale Hurston, novelist James Baldwin and radical anti-colonial psychologist Franz Fanon.

Then there was the ragbag of two centuries of great idiosyncratic polemicists – Tom Paine, HL Mencken, George Orwell, Christopher Hitchens. These profound individualists not only make up an important, if sometimes neglected, part of the humanist canon: they are at the heart of its non-conformist landscape.

Not only was this a far richer and more diverse tradition than I had realised, but it included many writers I had long known and admired, never realising they were humanists. Indeed, I can't help suspecting that many of these writers didn't realise it themselves, finding humanist positions through the workings of the intellect and imagination rather than commitment to a cause.

I'm pretty sure they're not the only ones. The world is full of humanists who don't know that they are, with more being minted every day thanks to the efforts of recruiting sergeants Bush, Blair and Bin Laden. The paradox is that, though there has never been a more important time to rally the forces in defence of rational debate, secularism and empiricism, those we most want to muster, humanists and humanists-who-don't-know-it-yet, are just the kind of people to give any call to arms what Bertie Wooster called 'the old fish eye'.

Humanists are sceptics. Above all, they believe in doubt. Probably. They won't rally round as a matter of course, they need convincing. This, among other things, is the purpose of New Humanist.

All of which recalls once again that old debate about what humanists are actually for. Is there a way to cast the humanist project as something more than just being anti-religious, anti-dogma, anti-irrationalism? There is, of course, enormous positive content in humanism, predicated on a belief in, and fascination with, humanity. But the danger of humanism trying to style itself as a 'positive project' (urgh), with a charter or a constitution (shudder), a set of demands (wince), is that this destroys in advance the possibility of alliances between individuals with widely divergent views, tastes and cultural baggage, who will happily come together to dissect, renounce, dispute and, yes, mock the unreasonable, the foolish, the unproven and unprovable, the inflexible, the supine and self-serving.

Humanists – whatever we call ourselves – cannot and, I think, should not expect to agree on what should be done. This is because a humanist is a person whose thought and opinions are dynamic, subject to change and contradiction, radically irrevocably open. It seems to me, from my perspective as new boy, that humanism is not a movement or an ideology but a cast of mind, an attitude to the world. Not a project with definable outcomes but a disposition. Although, of course, I could always change my mind about this.

This issue, I hope, encapsulates some of these ideas. We publish side-by-side right wing firebrand Simon Heffer and left-wing columnist Nick Cohen – hardly conventional bedfellows – united under the banner of independent thought. From Northern Ireland Newton Emerson dissects how Government policy finds it convenient to favour dogmatic sectarianism over the more complex (and potentially useful) perspective of the non-aligned, and Sami Zubaida analyses how the dynamic, open and sensuous sensibility of the Middle East is being forgotten. Laurie Taylor has traced the falling out between Michael Ignatieff and his human rights colleagues, a story which captures some of the complexity which ensues when big theoretical issues and human ambitions collide.

As I begin, New Humanist says goodbye to former editor and literary editor Jim Herrick, who has retired. For over 25 years Jim has been a tireless champion of freethought, and will continue to play an integral part in the world of rationalism. The last words are his: "Humanism is a way to live, to give meaning to life, and an understanding of our place in the universe."