I have considered myself very fortunate to have discovered Objectivism because it is to me very comforting to believe that morality is not something that comes “as a thunderbolt from the sky” or from divine revelation or anything else that like that, but rather, morality is, as Objectivism teaches, objective.
Hi Fred.
I know you’ve already had a bit of discussion, but I hope you won’t mind if I attempt to answer your OP?
In the first place, I’m glad that, although you may find Objectivism “comforting,” you have not stopped there. Is Objectivism right? That’s the question! 
I also understand from my personal experience that I do not know everything.
There are, I believe, two senses in which we may discuss “moral action,” and its relationship with knowledge.
In the first sense, I would say that “not knowing everything” is no bar to moral action. No one knows everything, and if that were required for moral action, then morality wouldn’t be very helpful as a concept. But what morality does require is that you make use of what you do know, to the best of your ability.
Morality, per Objectivism, is not something to be followed for its own sake. It is a guide to action for a particular purpose. That purpose is your own life – your survival and flourishing. Objectivism holds that you should do what you can to live the best life that you can.
Thus, when you are confronted with choices, when you make decisions, when you take actions, you need to be able to evaluate those choices/decisions/actions in terms of the effects that they are likely to have on your life, to the best of your knowledge and ability.
To do so is to do the very best that a human being can do.
There is a secondary sense of “moral action” that does rely upon omniscience, perhaps, or at least hindsight. We recognize that things are what they are, and that despite a man’s best effort, he may come to some conclusion that is false. A man may decide that X is the best thing to do for himself and for his life, and yet be mistaken. It may turn out that Y was actually the moral course of action, despite this man’s original conclusion.
In such a case, we would not fault this man morally for either his conclusion or his action. (Again assuming that he is operating to the best of his knowledge and ability.) But neither can we discount the role that knowledge plays in achieving the outcomes we desire.
However, since I do not know, and cannot know, everything, it seems to me that my concept of morality may change over time as I gain new knowledge – that what I consider as moral today, I may consider immoral tomorrow due to some new knowledge.
Absolutely. I expect that (if your experience of life has been like mine) your concept of morality has changed over time, according to both new knowledge and new approaches in thinking (or deeper thinking, or etc.).
Additionally, as I have gotten older I have noticed that my values have changed – that what I valued at age 16 is not what I value at age 25 and what I value now may not be what I value ten, twenty, thirty years from now.
Absolutely right.
Further, through personal experience and through reading, I have realized that different people have different concepts of morality and a wide range of different values.
Very much so. If this were not the case – if we all already agreed on morality, both in concept and application – I guess there wouldn’t be much here for us to discuss.
I must admit that this all makes me somewhat uncomfortable. If different people have different concepts of morality and my values and concept of morality can change what does this mean? What is moral?
We know that people disagree, granted. We know that one’s concept of morality can change, granted. What does that mean? It means that people reach different conclusions, and the same man may reach different conclusions over time.
The question of “what is moral?” can only be answered with respect to specific scenarios, or with respect to those general principles that we might try to draw from such scenarios.
To try to put this in terms of an analogy, consider competing theories of evolution. People may (and do) disagree about such things. Any individual’s theory of evolution may change over time, depending on what he knows and what he learns (and the time he allows himself to think about things, and his skill).
How do we decide “what is right (with respect to evolution)?” To answer that question, we must turn our attention to fossils and the factual record. Generally we can observe that the fact of “differing opinions” is no challenge to any particular theory of evolution; it only means that we must each individually do his best to assess the facts, and come to the best conclusions that we can.
The same is true with morality.
If I think that a concept is immoral and you think that the concept is moral, are we both correct?
No.
If we are both rational people and we both use our knowledge of reality, which was acquired by reason in accordance with logic, then are we both correct and the concept is both moral and immoral?
While in all cases I would counsel gaining knowledge, using logic to the best of one’s ability, and so forth – while we recognize that these are the means by which we have the best opportunity to reach the right answers, and thereby lead good lives – it is also the case that being a rational person, using knowledge, logic and the rest, does not guarantee that a man will arrive at a correct answer in any specific scenario.
You and I may disagree at any point as to whether something is moral. It doesn’t mean that we are somehow “both correct” (though we may both be “correct” in the sense of being correct to act upon our differing conclusions, having arrived at those conclusions through the proper methodology). It just means that we disagree.
It appears that this would be a contradiction. According to what I have read, Objectivism teaches that contradictions do not exist and that if one comes across an apparent contradiction one must check his or her premises and that, inevitably, one will find that one or more of the premises is in error. But how does this work? Is one of us using an erroneous premise and we just have to discover which one of us is in error and then we will both agree on the morality of the concept?
In a given disagreement, it may be the question of an “erroneous premise,” or it may be something else (like a misapprehension of the facts, or not yet having made some connection between facts, or so on).
But yes, the strategy for resolving such disagreements is that we make efforts to discover who is in error.
What if I think that your premises are in error and you think that my premises are in error, how do we overcome that impasse?
By the same manner in which we currently endeavor, in part. With recourse to logic, providing evidence, and so on. Discussion can help, as can making a sincere effort to reflect on claims, one’s own experiences, gaining new experiences, etc.
We strive to resolve contradictions, both between us and also within our own thinking, by appealing to reason.
Since I, as a human, and you, as a human, do not know everything, how do we come to a conclusion?
By the best use we can make of our minds, given what we know.
And if you and I do come to a conclusion, what is to say that either you or I will not come to a different conclusion at some point in the future if new knowledge about reality is learned?
Absolutely nothing.
We must be ready, willing, and able to revise our conclusions based upon what we learn. Our conclusions, if they are held in reason, are always contingent. They are contingent upon what we know, and the sense that we are able to make of what we know.
Given this, how can we say that anything is moral or immoral?
I feel like this formulation does not quite capture the actual spirit of your question.
“How can we say that anything is moral or immoral?” By appealing to the evidence we have and logic and so forth, that’s how.
But if the question is really"How can we say that anything is moral or immoral with absolutely no potential for error?" then the answer is “we cannot.” There is no level above “the best that we can do,” and there is no authority who can rule on whether or not we have come to some correct conclusion.
You can say that something is moral or immoral according to your best use of reason. There is no higher standard than that.