there's something to that. It seems to me its partially because we often make "doing science" a mental / virtual exercise. A process that is done with data and in the realm of one's head.

But doing science should includes all of our senses.

The idea of gemba comes to mind ( http://en.wikipedia.org/wiki/Gemba ): > The idea is that to be customer-driven, one must go to the customer's genba to understand his problems and opportunities, using all one's senses to gather and process data.

It's far easier to say that these are two different worlds of truth; one is more quantitative, the other is more qualitative, and the two are intertwined, building truth upon each other. Science does not meaningfully connect with the human race without a profound understanding and application of the humanities. Humanities do not meaningfully derive human truths without a profound understanding of the reality of existence.

The two are so important to each other that it's a wonder they have always resulted in such dichotomous opposing arguments throughout history. It is stupid, even; a human folly of ignorance and small-mindedness, only effectively resolved through a deep and liberal education of both types of knowledge at once. They are paradoxically opposing and yet deeply intertwined, and it would improve both areas of knowledge to have a deeper understanding of—and especially respect for—the other.

There need not be a well-formed simple logical statement to tell us this is true.

(When confronted with that, a typical rejoinder is that there is no 'should' -- life, consciousness, agency, will is all an illusion, all is meaningless and it reduces to physics in the end. The problem with that view though is that you have to throw out truth and knowledge too then)

Furthermore, all human behavior can be linked to activity in the brain, which can be studied by neuroscience. Finally, empirical surveys of human behaviors and moral opinions exist.

Therefore, morality is within the purview of science.

Science can talk about specific events ("John stabbed Joe with a knife"), it can talk about how people categorize them ("the stabbing had features X, Y, and Z that the typical mind categorizes at "murder"), and it can talk about how typical minds perceive and judge events it has categorized.

Morality is little more than an abstraction that human brains use to make social value judgements that help them fulfill their complicated set of values. If you can understand the values people have and the way these judgements help fulfill them, you've basically aced morality.

I'm not saying it's easy. I know several brilliant people working on this, and they're still getting surprises and uncovering edge cases. What I'm getting at is that statements like "most people think killing people is bad" can be reduced, with great difficulty, into statements about human behaviors and brain activity.

I doubt it, but in any case, the important point is that you can't do the same thing for "Killing people is bad." It's an important distinction. Most people think that homosexuality is bad, but we wouldn't want to conclude that it therefore is.

Suppose Alice gets in an argument with Bob, and stabs him. Is Alice worse off having done that? Is Bob? What is the impact on Bob's family, friends, and co-workers? Is society better off having a policy of arresting people in Alice's situation? And imprisoning them? Or socially disapproving of such action? When you learn that Alice stabbed Bob, how do you feel about it?

This is vaguely the lines which you'd take to talk about human morality in terms of behavior and mental states. This is not an exhaustive breakdown, and there's some parts that "morality" still claims afterwards. The point is that there's only so many things that people can mean by putting moral judgement on something, and there's nothing left when you've addressed them all. Addressing the pieces is usually done by going to human behavior and experiences.

Circling back to people thinking homosexuality is bad - we can make moral judgements about moral judgements. Statements like "'Thinking homosexuality is morally wrong' causes a great deal of pain for the people I care about."

Minor quibble: at one point, scientists believed that you couldn't prove whether or not two particles were identical in every respect. "I don't think that it's possible to prove X" isn't a proof that it's impossible to prove X. I'd rephrase that quote as "I don't know what a proof of X would look like."

If you answer all the subquestions, then whether it's right or wrong doesn't matter. Let's take a much simpler, analogous question to illustrate the process:

"If a tree falls in a forest, and nobody is around to hear it, does it make a sound?"

The controversial part of this is what people mean by "makes a sound". It's easier to break down here because there are only two senses of the it - vibrations in the air versus the qualitative experience of hearing. Once you've answered that it makes vibrations in the air but doesn't cause a hearing experience, whether or not it "makes a sound" doesn't tell you anything about what to expect.

Similarly, if you figure out what people mean by something being "right" or "wrong", you can use those pieces to cause the things that "rightness" and "wrongness" cause without caring about the overall judgement.

It may matter to a person who has a conscience.

I think the hangup people have is the mistaken idea that analyzing morality devalues it. But that's not the case. It does allow us to identify and discard obsolete morals (witness the sweeping acceptance of gay marriage), but those that survive are stronger for it.

Really, the whole dichotomous argument between the two is absolutely ridiculous. We need fewer people on the sides and more who are truly bridges.

"We waited until the blast had passed, walked out of the shelter and then it was extremely solemn. We knew the world would not be the same. A few people laughed, a few people cried. Most people were silent. I remembered the line from the Hindu scripture, the Bhagavad Gita: Vishnu is trying to persuade the prince that he should do his duty, and to impress him he takes on his multiarmed form and says, 'Now I am become Death, the destroyer of worlds.'"

Suicide bombers see a different purpose to their lives than (presumably) you and I do. By their own measure they are not doing badly, they are doing quite well.

Or consider Richard Dawkin's famous criticisms of Mother Theresa. Mother Theresa unashamedly put religion ahead material comfort among the poor she ministered too. To say she was wrong in so doing is not a statement of fact. It is a statement of ones personal values.

And objectively, suicide bombers are dead, which puts them far behind those of us who remain alive -- at least, by any sensible measure. Of course, when you unravel the story behind the average suicide bomber, you usually find that they were shamed or pressured into the deed, and in fact, have not accomplished, in committing a suicide bombing, all their own noble goals in life.

They are actually sad, pathetic people exploited by powerful clerics to be turned into little more than explosive puppets.

And yet the only argument I seem to get in favor of the worldview that (I believe) you and I largely share is "C'mon. Don't be silly.", which might be rhetorically effective, but is not evidence based.

The important difference is that I am willing to accept that I believe it without proof. You see and the parent seem to need to claim it's 'scientific' and 'rational' to embrace a worldview which values life, freedom, knowledge, etc.

Clearer?

We would have to agree on the definition of "true knowledge" to come to a complete understanding of each other's positions, but I'll take a stab at justifying my opinion that science is the only possible source for all "true knowledge". I'll define "true" as empirically tested and repeatable by others, and "knowledge" as statements about something tangible (e.g. brains), or about intangible concepts embodied within tangible things (e.g. brains thinking about ideas).

One needn't fully accept these definitions for the argument to hold, if one accepts that personal experience is a source of personal knowledge. Basically, if we consider all the claimed sources of knowledge, and consider which "way" of knowing applies in the most places, gains the most new knowledge over time, and has the best track record for producing societal advancements of knowledge and technology, the only "way of knowing" left standing is science.

You also mention "life purpose" and "knowledge is good" as counterevidence to science. But scientifically speaking, there is no objective purpose or objective good. There is only natural selection favoring the evolution of a desire for knowledge. That desire can be studied scientifically via neurology and related disciplines.

I wouldn't call the idea that "Knowledge is good", wisdom is better than ignorance, and freedom is better than slavery, etc. counterevidence. But I believe they are true things which I cannot prove via any sort of experiment, in particular because 'good' and 'better' are of necessity subjective.

It seems that we indeed cannot agree on a useful shared definition of "true". The laws of physics are ultimately indifferent to our notions of truth, and yet our notions of truth are instantiated as emergent phenomena within physics.