An ethical system consists of ethical principles that impose conditions on our behavior. The question is which ethical principles form a good, coherent ethical system. Are there rules to determine what ethical systems are good? This is a meta-ethical question, because it is about rules about rules: meta-ethical rules that determine which moral rules of conduct are good. The meta-ethical hand is a metaphor for five meta-ethical ground rules for constructing a good ethical system. Numerous ethical systems can be constructed. An example of a concrete ethical system which was constructed with the meta-ethical hand, is the system of the moral hand.
Everyone can construct an ethical system. But in order to avoid an anything goes ethical relativism as much as possible the meta-ethical hand imposes strong conditions. When constructing your ethical system, you must follow those rules that everyone must follow when constructing their ethical systems. If you can rely on your intuitions, then everyone can rely on their own moral intuitions. If no one may introduce ad hoc principles or farfetched rules at will, then neither do you.
We can construct more than one coherent ethical system. This means that we have a democracy of ethical systems. All equally coherent ethical systems are equivalent from a meta-ethical point of view. If different people adhere to different but equally coherent ethical systems, those people should seek to achieve an acceptable compromise through a democratic decision procedure, because no one can argue that their own ethical system and their own moral intuitions are more important than those of others.
The thumb: the principle of uniformity. The ethical rules and principles should equally apply to everything and everyone, without any exceptions. For example the right not to be killed against one’s will should be granted to everything and everyone. But this right is trivially met in the case of non-living objects and beings who have no will. No matter what we do with a non-wanting (non-sentient) and non-living thing, we always automatically respect this right. But for living and sentient beings it makes a difference.
The thumb principle is a very abstract principle that not yet decides what rules one must follow when constructing an ethical system. Just like we have to place the thumb against the other fingers in order to grasp an object, we have to apply the meta-ethical thumb of rule universalism to the other meta-ethical fingers in order to construct an ethical system.
The forefinger: compatibility and agreement with basic information. Basic moral judgments form the basic information in the construction of an ethical system. Basic judgments are for example moral intuitions that often spontaneously emerge in concrete situations or thought experiments. The forefinger basically says that ethical principles must refer to the basic moral judgments as good as possible and that we should give a strong priority to the strongest moral judgments. The strength of a basic judgment is determined by our willingness to give up the judgment when it conflicts with other judgments: if we do not find it so bad that the basic moral judgment does not fit into the constructed ethical system, then it is a weak basic judgment.
The middle finger: completeness and internal consistency. Each situation should generate one and only one final moral verdict. A final moral verdict is generated by the ethical principles when everything is taken into account. Consistency means “not (p and not-p)”. For example, a behavior in a specific situation cannot both be allowed and prohibited at the same time. If “p” is equal to “not (not p)”, then from consistency follows completeness: “p or not p”. So in any situation an act is either allowed or not. The ethical system should be able to generate a unique answer to the question which actions are permitted, prohibited and obligatory. This goes for each possible action in each possible situation.
The middle finger is the longest finger, so consistency is the most important condition in the construction of an ethical system. Inconsistent systems are not valid.
The ring finger: clarity. The ethical principles in the ethical system should be clearly formulated, so that they can be understood by everyone (who has the capacity of understanding) and they can always be applied without ambiguities. The meaning or interpretation of moral terms should therefore be clear.
The little finger: parsimony and simplicity. Just as the little finger can deviate a little bit from the other fingers, one may add additional, deviating ethical principles in an ethical system to a limited degree. One has to avoid as much as possible any artificial ad hoc adjustments (for example exceptions to exceptions to rules, or rules that apply only to a specific situation). One may therefore introduce only a little bit of complexity or artificiality, provided one is willing to tolerate everyone else adding artificiality to the same degree in the construction of their ethical systems (everyone, because one has to place the thumb against the little finger).
The palm: goodwill. One must show goodwill in constructing an ethical system, without arbitrariness and cognitive bias.
Five principles of anti-arbitrariness
Anti-arbitrariness (or regularity) is an overarching theme in the meta-ethical hand: it is present in all five fingers. Just as the moral hand creates five kinds of equality (anti-discrimination), so does the meta-ethical hand create of five kinds of anti-arbitrariness. Hence, meta-ethical anti-arbitrariness is analogous to moral equality (anti-discrimination).
The thumb: one should not arbitrarily limit the ethical principles to a random set of objects, beings or individuals. One should not choose victims at random.
The forefinger: one should not arbitrarily give weaker moral intuitions stronger priority. One should not change or exclude basic moral judgments at random.
The middle finger: one should not arbitrarily allow inconsistencies and gaps in the ethical system.
The ring finger: one should not arbitrarily introduce a vague ethical principle that one can interpret and apply arbitrarily in concrete situations.
The little finger: one should not arbitrarily add artificial, complex, ad hoc constructions to the ethical system.
An analogy with crossword puzzles
Constructing a coherent ethical system is like solving a crossword puzzle. A white box of a crossword symbolizes a particular situation or a moral point of view. A letter corresponds with a final moral verdict: an answer to the question what we may or should ultimately do in that particular situation, or what – all things considered – is valuable from the moral point of view.
Equivalent solutions of a crossword puzzle are equally correct, provided that they respect the following four rules.
The thumb: white boxes that are aligned next to each other have the same property, namely that they belong to one and the same word.
The forefinger: the completed words must refer to the given descriptions.
The middle finger: in a white box you must fill in one and only one letter. Consistency means not both a letter and a different letter. Completeness means either a letter or a different letter (so no empty white box).
The ring finger: the words must form existing, clear words.
The little finger: one has to avoid new words, farfetched words or ad hoc adjustments to words as much as possible, and give a preference to the most common words.
Constructing an ethical system is also similar to the way one ought to do science: deriving clear and mutually consistent principles (e.g. natural laws) from basic information (experimental data), thereby minimizing ad hoc constructions to the theory. A scientific theory should consist of universal laws that apply always and everywhere (the thumb), correspond as close as possible to the most reliable experimental data (the forefinger), are consistent with each other (the middle finger), are clearly defined (the ring finger) and are as parsimonious as possible (the little finger).