Springs of Human Action: Contrasting Aquinas and Hobbes

by Levi Crews

The springs of human action are the mechanisms by which humans come to act. The springs must include all inputs and the mechanisms themselves, and thus any discussion of springs will then be a discussion of these things. When we compare Aquinas and Hobbes with respect to these things, we will find that Hobbes has reduced (i.e. carved into a simpler model) Aquinas’s theory of the springs of human action. His reduction of the decision-making mechanism, however, is illogical, and accordingly his previous reductions about objects and understanding cannot be proven true. 

Let us begin our exploration of springs with objects external to an agent. Note, I use objects in the broadest sense, including both the physical (e.g. an orange chair) and the abstract (e.g. leisure). Surely, objects, by this use, are a sensible starting point for both Aquinas and Hobbes: Aquinas finds the source of agency in extrinsic “ends,” while Hobbes believes agency can only be established by our experience of the external.

We now focus on the former, i.e. Aquinas and ends. As already hinted, Aquinas views ends as the beginning of human action (Aquinas, Q.7, A.4). Ends, as things beyond the human being, are objects. According to Aquinas’s definition, every object is defined by its relationship to other objects (idea of integration). But here we encounter a seemingly infinite loop: Object A is defined (in part) by its relationship to Object B; Object B, by its relationship to Object C; Object C, by its relationship to Object A. In sum, these relationships are nontransitive. The only solution to this problem is the existence of some original, highest object to which humans can aim and by which all these goods can be immediately defined. And this is exactly what Aquinas gives us with his concept of happiness. Happiness, as the ultimate end, relegates all other ends to be potential means towards it. As the means to a normal end are always colored by that end, so are all ends colored by happiness.

Here we encounter Hobbes’s first reduction: Hobbes does not consider objects to have such relationships with some final end. That is, he does not define Object A by its relation to happiness in that Object A has the potential to approach happiness. Instead, every object is defined by what it presently is and is therefore separated from all that it currently is not (other objects) or can be (its potentiality). Without any potential, then, can objects tend toward anything? For Hobbes, no, because he claims there is no greatest good (Hobbes, Ch. XI). If there is no greatest good, there must be either a coalition of greater goods or all goods are equal. The first is illogical: the greater goods can be collapsed into the greatest class of goods, then providing a limit to which all other classes would approach. Then, Hobbes’s classification implies that all goods are equal in goodness, or lack thereof, and can objectively be considered value-neutral.

With objects and their relations now defined, to what extent do Aquinas and Hobbes require us to understand them in order to act? Here, the Summa must be carefully parsed. Aquinas gives us a dual idea of knowledge of the end, viz. perfect and imperfect. Perfect is knowing the end, its aspect, and its relation to the means; imperfect, knowing merely the end (Q.6, A.2). Aquinas argues that the former is only attainable by rational beings, whereas the latter can be achieved by beasts (Q.6, A.2). Furthermore, perfect knowledge leads to the perfect voluntary, in which the man can deliberate whether to pursue the end in question. Imperfect

Now we pose the same question to Hobbes. On the surface, Hobbes does admit that voluntary motions require some mental form: “. . . voluntary motions, depend always upon a precedent thought” (Ch. VI). Hobbes attributes these antecedent thoughts to imagination, i.e. the “relics” of sense (Ch. VI). Therefore, voluntary motion requires there to be a mental form of the object toward or away from which the action moves. In other words, Hobbes prescribes that an agent must understand X to deliberate if he will act or not act for X. But he does not admit the need for understanding with respect to the aspect of the act. He leaves no space for the decision to act for X or for Y, because he does not admit (a) a relation between X and Y to make a comparison possible, or (b) the possibility of asking why one should do X. For Hobbes, a train of thought is regulated by some desire, viz. for X, and thus cannot include an evaluation of whether Y may be a better desire (Ch. III).

Already, however, we are starting to see gaps in Hobbes’s logic. According to the above logic, sense (and, by extension, thought) must be noncognitive. That is, we are conscious of having a thought, but not of having the desire that is limiting and directing that thought. But what of delight? Recall, Hobbes labels sense as motion across our eyes, ears, etc. (Ch. VI). He then defines desire as the appearance or sense of that motion (Ch. VI). This implies interpretation of sense, or at least a sensing of sense. Therefore, there must be some mental faculty above sense that is assigning value to senses (and thus, objects) in order to make delight or displeasure. So much for the inputs.

Now we must discuss the mechanisms by which a human agent narrows his inclinations to a single action, i.e. the machinery of the spring. Note, Aquinas and Hobbes both include the possibility of having multiple inputs in an output function (i.e. action). For Aquinas, these inputs are reasons and the function is reasoning; for Hobbes, these inputs are passions and the function is deliberation.

Free choice is the essence of Aquinas’s theory of human action. We can choose between many ends and between many reasons for action. Accordingly, there is always a possibility of “otherwise.” Free choice, however, is not free will (McCabe, p. 68). We do not act unpredictably or haphazardly; we still obey a definable, predictable function. Let us propose such a function. At the most basic level, Aquinas admits the presence of passions, and he attributes them to external objects (Q.6, A.1; McCabe, p. 72). We will henceforth define these passions as integers, with positive and negative values for appetites and aversions, respectively. We then encounter the will. For Aquinas, the will is an intrinsic principle that must be aimed at an end, but it need not be the first principle of action simply (Q. 6, A. 1). So, we may define the will as a variable  that can be present anywhere within the function and varies according to the reason of the agent. In other words, the will is a variable with a domain completely within the agent’s rationality that can overrule the sum of passions. For example, take the action function:. The integers (3, -4, and 2) are appetites and aversions of the given values. The variable  is the will, which may coincide with the sum of passions (i.e.  = 1, so  would be positive), or it may override the sum of passions (  -1, making the sum negative and the action undone). The special character of the will is that its value comes from within the agent; the passions are valuations of external objects.

Hobbes, on the other hand, uses a reduced function. For him, voluntary action is a byproduct of deliberation, which reckons only the relative positive values of appetites with the negative values of aversions. For instance, Andrew sees a pint of vanilla ice cream in Bethany’s freezer. Andrew is hungry for ice cream, so we can assign this appetite a value of +2. He does not, however, want to steal because Bethany may return, catch him in the act, and label him a thief—an aversion of -3. He then notices Casey, a pretty girl whom he likes, enter the room. He recalls that her favorite flavor is vanilla, and he thinks that she would enjoy sharing the ice cream with him. The desire to please Casey is an appetite of +5. Andrew deliberates: 2 – 3 + 5 = 4. This sum is a positive value, i.e. an appetite. He will then take the ice cream. (Note: this is a quite simplified example, but an account of all possible passions in this situation would be fruitless).

The final passion—that which is left after all other passions have cancelled out—is that which Hobbes calls the will. In the above example, the will to take the ice cream rests in the desire to please Casey and to (hopefully) one day secure a date. Deliberation, however, if it is a sum, must be commutative. That is, 2 + (5 – 3) = 5 + (2 – 3) = -3 + (5 + 2). This raises three problems for Hobbes: (1) how can the will be the last passion if any passion can be last? (2) how can a -3 aversion (e.g. not wanting to be caught) be the will for a +4 appetite (e.g. stealing the ice cream)?  and (3) if order is necessary, how can anyone recall the order (surely one is not passionate slowly)? The answers to all three questions rests on a retrospective determination of will. The will is only identified in the deliberation function after deliberation has occurred, not during. Thus, the order of deliberation can be rearranged so that the most overwhelming appetite or aversion is last. In that case, order doesn’t matter, and the will is always last because you can retrospectively rearrange it to be so.

It is important to note that nowhere in the above mechanism is rationality used. Recall, Aquinas represents the rational will with a variable . When he considered animals or the manic, however, he removed this variable and called acts common to man and animals by the name “Passions” (Q.6, Introduction). We now begin to see the reduction: Hobbes thinks this second mechanism to be the only device. For Hobbes, then, both men and beasts can deliberate (Ch. VI). We must note, too, that Aquinas matched passions with imperfect knowledge, forming the imperfect voluntary (Q.6, A.2). For Hobbes, passions are the inputs for all voluntary action.

Hobbes justifies his mechanism with the claim that since all voluntary actions are not rational, the will cannot be the rational appetite (Ch. VI). To explain Hobbes, we must broach the question of human mistakes, i.e. how do the mechanisms go awry? Hobbes’s mechanism is devoid of reason, so it’s no wonder—even to Hobbes—that it goes astray. In fact, this is exactly why he designed it as such: people are irrational too often for their voluntary decisions to have always been rational. But Aquinas already supplied a counterargument to this objection in his Summa. He claims that we can misapprehend that which is good because we cannot see all consequences of our actions (Q.8, A.1). Therefore, those actions that appear irrational seem so only because our rationality is blind to the future. For example, David may enter a bathroom with the expectation that it is a men’s room. Edna, however, will hardly expect that reason before she screams over David’s seeming irrationality. Most strikingly about this counterargument, however, is that Hobbes admits it, too! He notes that the passions with which we deliberate are “raised by the foresight of the good and evil consequences” of the act (Ch. VI). He continues to then say how she who has the most reason is she who will be able to foresee these consequences most accurately (Ch. VI). It appears, then, that Hobbes need not—and possibly could not—strip reason from deliberation.

This is not Hobbes’s most prominent inconsistency related to reason, however. That lies in his valuation of passions. What exactly can be a passion? Hobbes defines passion as an endeavor towards that which causes it (Ch. VI).  An endeavor, as preliminary forms of voluntary motion (Ch. VI). Voluntary motion, as beginning principally with imagination (Ch. VI). Imagination, as decaying sense (Ch. II). Sense, as impressions of objects upon a human agent (Ch. I). Recall, objects, for Hobbes, are objectively value-neutral. That is, there is no intrinsic morality or valuation of good that objects hold for all. How, then, does Hobbes suppose we create passions toward good or away from evil, if he establishes no mechanisms for these motions? In other words, how does an object obtain value to pull us towards or push us away from it? Simply, it cannot unless our impressions are filtered subjectively. And this would be perfectly reasonable, and Hobbes may even agree, but he has not described a filter—likely because he cannot. He leaves no room in his system for an interpretation of sense, because sense is, to him, noncognitive (see above). By this logic, Hobbes’s method of deliberating necessarily self-destructs.

If deliberation is not a reasonable reduction, what about Hobbes’s limitations on objects and understanding? To explain this, we must mention how value is attached in Aquinas’s mechanism. For Aquinas, happiness must be aimed at by all agents (Q.9, A.2). Ends, then, obtain value relative to their ability to serve as means to happiness (Q.6, Introduction). Their ability to do so is necessarily evaluated by reason, and mistakes are made only because reason can be blind to consequence. For Hobbes, then, if passions must obtain value, the most logical mechanism is reason. If reason is now required for deliberation, then understanding need be required, for an agent cannot reason without an input of knowledge. If we must understand objects, must we understand them in relation to something? Yes, because the values of appetites and aversions must be relative to one another.

Surely we can save Hobbes; the preceding interpretation must not be the only one. He has left space for there to be a cognitive sense (viz. Delight), we have seen that he could have included reason with his mechanism, and maybe his appetites and aversions don’t have relative value, i.e. they may just be +1 and -1. Let us quickly focus on that last idea. By this model, objects need not be related, because their value isn’t bigger or smaller. Accordingly, all that is required to act toward something is more appetites than aversions. But this is outrageous. Simply put, two people desire things to different extents. My appetite for ice cream is surely not exactly the same as yours: so they can’t be both +1. With that disproved, let us return to the first two. If we include reason and make sense cognitive, we have arrived back at Aquinas! The only way to save Hobbes’s reduction is to unreduce it.

It is clear that Hobbes has carved Aquinas’s springs into much simpler, more brutish ones. In fact, Hobbes has reduced rational human agent to simply “human agent” with the mere capacity to be rational. But so much of human action relies upon reason, that this reduction cannot be so. The separation of man from animal is vested in our reason; Hobbes should have discovered that taking out reason is impossible, for we are undeniably different from animals.