such challenge. In other words, there are no moral absolutes. That is the point of strong
pluralism.
Weak moral pluralism is the view that there are at least some humanly possible basic
moral principles which make incompatible demands such that one could not coherently accept
them all, and it is humanly possible that there would be no unanimous agreement among non-
pathological, relevantly-informed adults about how to choose between them. The difference
between weak and strong pluralism is the difference between “some” and “all.” The weak
pluralist could admit that there are some basic principles that all would accept, at least in the last
analysis, but that not all basic principles enjoy this status. The strong pluralist, by contrast,
claims that all humanly possible basic principles fail to be absolute.
Absolutism is the view that there are basic moral principles which would not irresolvably
conflict with any humanly possible values. For these principles, reasonable discussion is possible
to the point of wholly resolving any disagreement. One can also speak of weak and strong forms
of absolutism. If all value conflicts are ultimately reconcilable, then strong absolutism is true. If
this is only true of some value conflicts, then weak absolutism is right. To espouse strong
absolutism is to deny strong pluralism. Weak absolutism and weak pluralism are mutually
compatible, although the extent to which one applies is the extent to which the other does not.
If weak pluralism is the topic, then pluralism can be a matter of degree: Pluralism pertains
to the extent that there are basic moral principles prone to this sort of undecidability. And, of
course, these definitions should be supplemented with the normative claim that the incompatible
basic principles reflect conflicting obligations.
The definition of moral pluralism in terms of basic moral principles may seem to require a
psychological assumption. But it doesn’t. The question is not necessarily whether basic moral
principles enjoy psychological reality, for basic moral principles may be an abstraction from an