Rules, for Wittgenstein, reveal nothing new. In the “rule-following paradox” of the Philosophical Investigations, Wittgenstein asks how a rule can tell one what to do. He finds that a given rule can be both in accord and disagreement with any action; as such, the rule itself is both a tautology and a contradiction—it tells us nothing about what we should do. Instead, rules operate as signs of a particular interpretation. They imply a process, a process contained in them as a possibility. “Custom,” or the typical way a rule is interpreted—how most people follow a rule—determines the possibility which a rule is understood to signify. Wittgenstein transforms the philosophical question of rules as an imperative to one of general social action. One follows a rule simply because, given that rule, most people do some given action. Rather than ask how rules are an imperative, we are now to ask how “custom” chooses the interpretation of a rule and why one follows custom. The philosophical question becomes a sociological one, and philosophy loses one of its most vibrant questions—the question of how I know what I am to do, based on a principle.
Wittgenstein explicitly raises two problems in this section. The first, stated by an interlocuter in remark 198, is: “‘How can a rule teach me what I have to do at this point?’” The second, stated in remark 190 in response to an example, is: “What is the criterion for how the formula is meant?” The former asks how rules can be an imperative; the latter asks how one knows what one is meant to generalize, given particular set of examples. The latter question rests on the first. One only needs to find the generalizable principle within a rule if a rule is an imperative for action.
Remark 201 addresses the question of rules as an imperative. Wittgenstein writes, “no course of action could be determined by a rule, because every course of action can be brought into accord with the rule…it can also be brought into conflict with it.” Here he argues that a given rule can both justify and undermine any action. Because any action can either agree or disagree with a rule, a rule cannot inform any action. Rules are interpreted not according to their content since their content says nothing. They cannot be an imperative; our first question is moot.
In remark 198, Wittgenstein writes, “a person goes by a signpost only in so far as there is an established usage, a custom.” Rules are interpreted according to their custom rather than what they say. In remark 217, Wittgenstein claims that justifications for interpreting a rule in one particular way can be continuously exhausted, for there is no fundamental interpretation, and one resolves with one’s interpretation of the rule by merely declaring “this is simply what I do.” Rules are follows in a given way because people follow them in such a way.
Since rules as interpreted by custom and cannot give an imperative, rules themselves are used as signs of a process. Customs work to associate the sign to a process. Like a machine, the rule stands for a predetermination of movements. Described by Wittgenstein in remark 193, machines are symbols of a predetermined set of movements. The predetermined movements, “already present,” exist only as a possibility, as Wittgenstein elucidates in remark 194. A rule expresses the possibility of its interpretations. These interpretations are various processes, predetermined movements which a rule can signify. The “right” process signified by a rule, or the following of a rule, is a process, narrowed by custom, signified by a rule.
We have changed the question of rule-following into a problem of customs. We still do not know how a given custom comes to be—how one interpretation of a rule wins out. How does custom operate to allow for only some interpretations to stand for a rule? How does custom select the principle to generalize? These questions seems to be of a different kind than what Wittgenstein initially raised—they ask about how social convention comes to be and acts upon the individual. They seem sociological rather than philosophical. By raising this paradox, Wittgenstein pushes out a fundamental philosophical question—how do I know what I am to do, based on a principle—from philosophy.