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Legal Theory Lexicon: Motives and Functions

By Lawrence Solum

Introduction

The law frequently deploys the idea that actions, events, and communications have motives, purposes, or functions. Consider the following list of questions:

  • What is the goal of that statute?
  • What function did the clause of the contract perform?
  • What was the purpose of the military intervention in Venezuela?
  • What motivated her sale of shares in the company?

 This Lexicon entry explores an important distinction between subjective motivations, on the one hand, and objective functions, on the other. These concepts are deployed in a wide variety of legal contexts, playing an important role in theories of statutory interpretation, the context of judicial review, and elsewhere. The basic idea of the distinction is simple. When we think about purposes or goals, we can distinguish between motives (psychological states) and functions (objective properties). The motive for enacting a statute might be “to get campaign donations from a special interest group,” but the function of the statute might be quite different, “to enable the production of greater quantities of petroleum.”

As always, this Lexicon entry is written for law students, especially first-year law students, with an interest in legal theory.

An Example of the Distinction in Action: Statutory Interpretation and Construction

Simplifying, let us assume that there are three basic approaches to statutory interpretation and construction:

Textualism holds that the legal content of statutory doctrines and the decision of statutory cases should be determined by the meaning (communicative content) of the statutory text.

Subjective Intentionalism holds that the legal content of statutory doctrines and the decision of statutory cases should be determined by the motives (subjective intentions) of the legislators who enacted the statute

Objective Purposivism holds that the legal content of statutory doctrines and the decision of statutory cases should be determined by the function (objective purpose) of the enactment.

Let’s put textualism to the side and focus on the difference between subjective intentionalism and objective purposivism. One might think that intentions and purposes are more or less the same thing, and hence that intentionalism and purposivism are just different names for the same theory. But that would be a mistake. Subjective intentions are motives or psychological states. Objective purposes are functions that statutes are designed to achieve.

The subjective intention of a legislator might have the same content as the objective purpose or function that the statute was designed to achieve. For example, a legislator might vote for a gun control statute that prohibits the ownership of assault rifles in order to reduce the incidence of casualties from mass shootings, and that might also be the function that the statute was designed to achieve. But motive and function may be quite different. The assault rifle statute might have been motivated by the legislators’ desire to compromise between two important constituencies, hunters and gun control advocates.

Consider a hypothetical involving the application of the assault rifle statute to a new weapon, a rifle that looks like a traditional hunting rifle but has the same capacities as a military assault rifle. A judge applying an objective purposivist approach to statutory interpretation might conclude that the new weapon is an assault rifle because it has the same level of casualties as military-style assault weapons. But the application of subjective intentionalism might lead to the opposite result. The new weapon looks like a hunting rifle and the political motivations of the legislators (their subjective intentions) did not extend to prohibition of rifles marketed to and primarily used by hunters.

What are Functions?

The basic idea of subjective intentions or motivations is relatively easy to grasp. Humans act from motives all the time! But the notion of a function or objective purpose is a bit trickier. One might be tempted to say that functions are just motivations in disguise. Or one might have the thought that objective purposes are really just hypothetical or counterfactual intentions.

One way to get at the notion of function or objective purpose is by thinking about artefacts–things that are designed to accomplish some purpose or to serve some function. A classic example is a clock. Clocks are designed to serve a function, to tell time. But it need not be the case that any particular clock does tell time: if there is a power outage, the clock built into my stove no longer tells time (until it is reset and restarted), even though that is its objective. Moreover, a clock can have the function of telling time, even if the clock maker did not have the subjective intention that it should do so. We can imagine someone building a clock from a set of instructions in order to produce a beautiful object and without any intention to build a clock that actually works–even if the clock does in fact tell time. And we can even imagine that the set of instructions was produced by an artificial intelligence (such as a large language model) that lacks subjective intentions (motivations) altogether!

So, a legislature might enact a statute that was drafted using a model statute from another jurisdiction. The legislative staffer who did the drafting could simply have copied language from the model without giving any thought to functions that the statute would serve, and members of the legislature could vote for the statute on the basis of political motivations–again without thinking about the functional construction of the statute.

Conclusion

The distinction between motive and function is a basic one deployed by the law in many contexts, although this Lexicon entry has explored the distinction in the context of statutory interpretation and construction. The key to grasping the distinction is the idea of function, and that idea is best approached via the notion of an artefact designed to perform a function.

Related Lexicon Entries

∫Bibliography

  • Beth Preston, Artifact, Stanford Encyclopedia of Philosophy, https://plato.stanford.edu/entries/artifact/

Link to the Most Recent Version of this Lexicon Entry

(First posted on March 15, 2026)

Lawrence Solum

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