Risk management through diversification is a totally different use of the word diversification, and that can be followed by a single person also; I don't have to have two contradictory opinions to not invest all my money/resources/time in one basket.
Of the 3 examples you mentioned:
1 is not something people actively "think" about, but is in a sense "automatic", although there is disagreement.
If you feel 2 doesn't have a correct answer, then it seems you're endorsing some form of moral nihilism, in which case the question is meaningless. (Note: this is the position which I myself hold.)
For 3, people are not actually looking for the "best" answer; they want a satisfactory answer. There is a best answer, but it's usually not worth the effort to find. (For any sufficiently complicated problem, of course.) There may be multiple satisfactory answers, but it's not a sign that someone isn't thinking if everyone comes up with the same satisfactory answer.
Risk management through diversification is a totally different use of the word diversification
Totally different than what?
1 is not something people actively "think" about
Sure they do, but to make it more stark let me change it a bit: "Am I pretty?"
More generally, this example represents the whole class of subjective opinions.
If you feel 2 doesn't have a correct answer, then it seems you're endorsing some form of moral nihilism
Not quite, just rejecting moral realism is quite sufficient here. But in any case, people do think ab...
Another month, another rationality quotes thread. The rules are: