Okay, I like this lecture quite a bit. Sam Harris is a pleasure to listen to and quite charismatic while making a number of excellent points.
What bugs me however is a matter of semantics, and I find it deeply disturbing that it is even an issue. What he is talking about is less science and more philosophy. And it is really basic philosophy at that. At some point this disconnect arose, creating a fissure between science (which could apparently no longer go under its old name of 'natural philosphy') and what we now refer to as philosophy. And for an unknown reason there is the idea that philosophy is just opinion whereas science is fact. Which seems to be a completely bogus distinction. Philosophy relies no less on argument, logic, and indeed demonstration than science, what distinguishes them is the use of the scientific method. It is not possible to employ the scientific method on the study of a noumenal concept like morality. But does that mean it is impossible to employ reason? No. Nor does it mean it is impossible to set up a concrete ethic. It just means that it is not science. But there is nothing wrong with that.
The entire long history of moral philosophy has in fact held that we can say concrete things, demonstrate logical consistency, and move beyond reliance on opinion in moral discussions. From Aristotle to Immanuel Kant and beyond we have had many people who have dedicated a great amount of thought and work to defining concrete moralities. The problem comes from the fact that in recent years this has begun to stagnate. Especially in the united states. From the late 1800s on, potentially spurred by the schism over Darwinism (source: Darwinism Comes to America by Ronald L. Numbers), there has been this vast anti-intellectual movement amongst religious groups. In 1850 the idea of biblical literalism and young earth creationism for example were fringe concepts that have, today, taken over a majority (or possibly extremely vocal minority, I don't have the numbers) of Christianity. This shift has been felt by education. Religious groups have attacked philosophy, downgraded its validity, in an attempt to set up 'divinely revealed' ethical structures as having just as much validity as those described by reason, and derived from a priori principles.
This is felt nowhere so much as in the way we educate our children. Religion grudgingly permits what science it cannot censor to be taught, but keeps a tight leash on captive moral philosophy lest we realize that commandments of God may not have the same validity as the morality of humans. And it is an absurd idea. Numerous great moral philosophers were also religious people, they were not however literalists or dogmatists. As such there was no conflict for them to both believe in God and at the same time logically derive moral principles of action. It amazes me that you can't get through highschool without taking science courses but at the same time you can't take a course on ethics.
Harris' point seems like an amazing revelation and a radical idea, but only because in the last one-hundred years or so we have fallen into a dark age where moral philosophers are relegated to small departments and the pages of academic journals. They are there. We have trained experts. They have been shouting that these questions have answers, but the laypeople seem unwilling to listen. Hell, a logically derived freedom and equality based universal ethic has been lying around since Kant came up with the categorical imperative in the 1700s.
Of course the way things are going there is a rising tide that doesn't want to listen to experts in any field and (bolstered by the success of unjustly relegating morality and philosophy to the field of opinion) they are attempting to move on science next. But that is a different discussion.
tl;dr version: I am really happy about this video says, but I am extremely sad that it has to be said because it is something we should already know.