The condemnation of eugenics went too far and it needs reassessment, a leading scientist is arguing.

Eugenics is the science of using genetics ostensibly to "improve" mankind.

The idea that this was a good thing had wide currency throughout the early part of the 20th century.

However, the concept got a bad name in the 1930s when the Nazis determined that they would use it to create a "master race".

Now Richard Lynn, Emeritus professor of Psychology at the University of Ulster, has written a book in which he says it is time for a re-think.

He told the BBC that advances in medical technology, such as the pre-natal diagnosis of pregnant women for genetically disordered foetuses, meant that in a sense eugenics was already being practised.

"The general principle of eugenics, that we could improve the genetic quality of the population need taking seriously.

"The new medical technology of eugenics is going to take off, because it satisfies the needs of individuals, both for themselves and as parents.

"Parents would like to have children who are free of genetic diseases, and potentially in the future they will want to have children who are intelligent.

"This is serving people's needs and wishes. As the technology comes on line to allow them to do this, people will take it up."

Prophesy of despair

Dr Tony Cole is a consultant paediatrician who works with Downs children and is a member of the Guild of Catholic Doctors.

He said that idea that people would inevitably exploit new technology as soon as it became available was a "prophesy of despair".

Dr Cole stressed that the idea of genetic enhancement was specifically forbidden by current regulations.

"If you are going to manipulate the genetic composition of an individual you are changing not only that individual, but perhaps a thousand descendants of that individual.

"This is so-called germ line manipulation, and it is very tightly regulated because it could be hideously abused."

He said countries coming together to try to find an acceptable way forward.

"The fundamental issue is a question of justice between generations. Do we control the next generation in that sort of way? Are they are a sort of custom-specified commodity?"

Dr David King, a geneticist and coordinator of the watchdog group, Human Genetics Alert, said: "We find Richard Lynn's claims that some human beings are inherently superior to others repugnant.

"With the new power of genetics, it is more important than ever that we avoid a return of eugenics, under the guise of free reproductive choice."