The indented text below is Dr. Benson's second question to me based on the text of my opening remarks in the Chesterton debate. My response follows.
As did mid 19th Century secularists you seem to suggest that "evidence based public policy" favours the non-religious viewpoints. Many things that matter to us in life and government policy are not, however, susceptible to "evidence" assessments free of moral commitments. Moral debates about such issues as euthanasia, gender-selection abortion or certain kinds of tax policies are not resolved by "evidence" cut off from competing interests and beliefs. In short: we choose how to weigh evidence against a moral background based on our beliefs. Your approach gives atheists and agnostics the ability to have their beliefs effective in relation to moral public policy formation but not religious people's: how can that be fair?
Embedded in this question is a false assumption - that I am proposing we exclude the ability of religious politicians to use their moral judgement. I have never advocated for such a position, nor has any prominent secularist organization. However, all politicians, religious and non-religious alike, have a responsibility to express their goals and concerns in universal values, rather than in the terms of their particular creed. This allows all people, of all backgrounds, of all faiths (including those having none) - to fully participate in the political arena. Mr. Benson asks: How can that be fair? I respond: What could be more fair?
Mr. Benson is correct that I favour evidence based public policy. We both hold the view that while evidence must inform public policy, it cannot dictate it. One key role of elected officials is to determine the extent to which competing interests benefit from a proposed law or policy. There are often trade offs that lie at the heart of a politician's job - such as whether to raise or lower taxes (and which ones), increase or decrease spending (and where), run a surplus or deficit - all in an infinite number of possible combinations. We should use knowledge to foresee, as best we can, the consequences of various options, but ultimately a decision will be made due to priorities that come from a philosophical or moral foundation that is not based on evidence alone.
Religious groups are allowed to have their say in the public square, even if they give explicitly religious rationales for their positions. By the same token, however, politicians and judges are under no obligation to accept arguments whose only justification is religious in nature.
While same sex marriage was being considered in Canada a decade ago, religious voices were a significant part of the discussion and religious groups were very active in the debate. Canada's legislature, its courts, and society overall did not end up agreeing with the religious perspective – but all interested parties were able to express their moral beliefs about the topic.
More recently, in October, an interesting case was heard by the Supreme Court of Canada about whether it is legal for a municipality in Quebec to start its meetings with a prayer. The Court has yet to render its verdict.
In addition to the plaintiff and the defendant, there were several interveners that presented before the Supreme Court: the Canadian Secular Alliance, the Canadian Civil Liberties Association, the Evangelical Fellowship of Canada, the Catholic Civil Rights League, the Faith and Freedom Alliance, and the Association of Catholic Parents of Québec. It is simply not the case that "religious beliefs are not permitted in the public sphere." Religious voices are being heard, even if their arguments are sometimes rejected. Religious organizations engage all levels of government, through direct lobbying, raising money, taking out advertisements, voting with their feet, just like any other group. This cannot be accurately described as discrimination.
Mr. Benson: I am here tonight because I am intensely concerned about fairness. To ensure justice and equal participation from all members of society, we need only apply the criteria that you yourself laid out just a few minutes ago - that we judge arguments based on their fairness, reasonableness, and general applicability. If we combine that with the ideas from my opening address - that public policy be based on the principles of human experience, objective evidence, reason, human empathy and compassion - then we have a way to determine which laws, actions, and policies are in the common interest, whether one's altruism is motivated by religious faith or whether the inspiration to public service stems from a humanist philosophy. This is democratic. This is just. This is fair.