These questions are about Chapter 2 of Harry J. Gensler's book on FORMAL ETHICS (Routledge: 1996). These materials are copyrighted (c) 1998 by Harry J. Gensler; but they may be distributed freely.What is logicality?
I won't have any questions on Section 2.4 (Conjunctivity), since this gets rather technical.
Logicality is the requirement that we be logically consistent in our beliefs. By logicality, we are not to accept incompatible beliefs -- and we are not to accept a belief without also accepting its logical consequences.The don't-combine form
The idea is important and useful. But there are some tricky points about how to formulate it adequately. The distinctions that we develop here will be useful for other formal principles -- like the golden rule.
We need to formulate consistency norms using a don't-combine form (you ought not to combine this belief with that belief) -- not an if-then form (if you hold this belief then you ought not to hold that belief).Qualified consistency
The don't-combine form simply forbids an inconsistent combination of beliefs -- but doesn't tell us what to do if we are inconsistent. The if-then form generally leads to absurdities and contradictions.
The duty to be consistent is subject to various qualifications. Consistency is a prima facie duty and can be overridden by other considerations; perhaps if we're consistent then Dr. Evil will start a world war -- or we'll get painful headaches. Or we might be psychologically unable to be consistent at a given moment; but we can't have an obligation to be consistent if we're incapable of this.Why be consistent?
All our consistency duties (even the golden rule) are subject to the same implicit qualifier. Section 2.3 of the book formulates this more carefully and compares it to a qualifier needed for logical principles.
We might answer this question in various ways. We might strive for consistency because this promotes our desire to be rational -- or our desire to promote our self-interest (and avoid paralyzing confusion). Or we might argue that consistency promotes the social good, or that inconsistency is intrinsically bad and thus ought to be avoided. Or we might base the consistency requirement on social conventions, ideal observers, or God's will. Or we might see the requirement as self-evident, as coherent with our moral intuitions, or as presupposed by any form of reasoning. Or we might accept it as expressing our feelings or how we've decided to live.