The West is facing a “Civil War” over values and religion, according to a leading Spanish academic.

Professor Francisco Contreras, of Seville University, said that in both Europe and the US the big issues of the 21st century would be family structure, bioethics and the role of religion in society.

He was speaking on Wednesday at a session of the European Ideas Network, a series of seminars sponsored on behalf of the European People’s Party by Gay Mitchell MEP.

Professor Contreras said that, with the collapse of the socialist project to remake the economy, the Left had “now replaced socio-economic revolution by sexual, moral and cultural revolution”.

He contrasted the way the battle of ideas is played out in the US and in Europe.

While the US had a vigorous family values movement, in Europe, the Catholic Church often found itself “pathetically alone” when it came to defending traditional values, he said.

Christian Democratic parties in Europe, Professor Contreras continued, remained “under the spell of the 20th century paradigm; they think the major differences between Right and Left still have to do with the way material production is organised”.

European centre-right parties, when it came to cultural issues hadn’t developed “alternatives of their own, neatly distinguishable from those of the Left,” he said.

“The Left leads the cultural initiative, and the European Right seems resigned to a passive role,” Professor Contreras added.

He added that secular, left-wing governments in Europe had been “undermining and blurring the distinctive legal status that used to be accorded to the lifelong union of one man and one woman” through the liberalisation of divorce, legalising same-sex marriage and making cohabitation the legal equivalent of marriage.

However, those who defend traditional marriage, he pointed out, had plenty of arguments to deploy: children raised in marriage did better on a range of outcome measures, educational, emotional and economic.

“A society with less stable marriages is a society with less children, and with worse educated ones,” Professor Contreras said.

In his talk, he also rejected the suggestion that the struggle between violent Islamism and the West was a religious clash. Instead, it was the very secularism of the West which hindered its dialogue with other societies.

He said: “Western secularisation hinders the dialogue between the West and other civilizations (as these continue to be religious). Pope Benedict XVI put it sharply: “In the eyes of [the rest of] the world’s cultures, the absolute secularism that has developed in the West appears as something profoundly odd. They are convinced that a godless world has no future”.