Lichtenberg’s Point

In: Grazer Philosophische Studien
Author: Boris Hennig1
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The author argues that when Lichtenberg recommends saying “It is thinking” instead of “I am thinking”, he is not suggesting that thought might be a subjectless occurrence. Lichtenberg’s point is, rather, that we are often the passive subject or medium of our thoughts. The author further argues that Descartes’ cogito argument is not affected by this point, because Descartes does not claim that we must be the active subject of all our thoughts. Moreover, the author suggests that the cogito argument operates with the notion of a qua-object: it consists in the move from “I am thinking” to “I-qua-thinking am”. Seen in this way, the cogito argument by itself leaves entirely open what might be true of me insofar as I am not thinking.


The author argues that when Lichtenberg recommends saying “It is thinking” instead of “I am thinking”, he is not suggesting that thought might be a subjectless occurrence. Lichtenberg’s point is, rather, that we are often the passive subject or medium of our thoughts. The author further argues that Descartes’ cogito argument is not affected by this point, because Descartes does not claim that we must be the active subject of all our thoughts. Moreover, the author suggests that the cogito argument operates with the notion of a qua-object: it consists in the move from “I am thinking” to “I-qua-thinking am”. Seen in this way, the cogito argument by itself leaves entirely open what might be true of me insofar as I am not thinking.


Lichtenberg famously writes that instead of saying “I am thinking”, one should say “It is thinking”, and he is generally taken to suggest that Descartes’ cogito argument is therefore flawed. In the following, I will take a close look at the entry in Lichtenberg’s notebook where this happens. I will distinguish three versions of Lichtenberg’s point and ask which of these versions does what kind of damage to Descartes’ argument. I will conclude that the cogito argument would be blocked only by the most extreme version, the one that takes thought to be a subjectless occurrence. Any weaker version of Lichtenberg’s point will leave a version of Descartes’ argument intact.

1 Thought and Lightning

At some point in 1793 or 1794, Lichtenberg writes the following (Sudelbuch K 76):

[a] We become aware of certain representations that do not depend on us; others we believe at least depend on us; where is the boundary? We only know of the existence of our sensations, representations, and thoughts. [b] One should say “It is thinking”, as one says “It is lightning”. [c] To say “cogito” is already too much, as soon as one translates this with “I am thinking”. [d] To assume the I, to postulate it, is a practical need.1

It will pay off to thoroughly review everything that Lichtenberg is suggesting in this passage.2

[a] He begins with the observation that some of our representations, our thoughts and impressions, literally occur to us. We don’t make them according to a plan, like we make paper airplanes, and we don’t perform them as we might consciously and deliberately perform a dance step. Rather, many of our thoughts happen to us: they cross our minds, dawn on us, offer themselves, strike us.

Lichtenberg rephrases this by saying that all we know about our impressions, representations, and thoughts, is that they occur. We merely know of their existence. What do we not know, then? Perhaps Lichtenberg means that in contrast to their existence, we don’t know their essence, but nothing in the immediate context points to this. More likely he repeats and generalizes a point that Hume made more than fifty years earlier about sensations: they arise in our minds “originally, from unknown causes” (Treatise I,i,2; SB 7). We merely notice their presence in our minds, as opposed to knowing what brought them into existence. We tend to assume that they were caused by external objects, but we do not actually know this, and we cannot possibly have any evidence, in the form of a further sensation, that would settle the issue once and for all. All we know is that as a matter of fact, these sensations pop up in our minds without being occasioned by anything else in our minds. Now if Hume is right and everything in our minds derives from some kind of sensation, and if sensations seem to come out of nowhere, then we don’t actually know the ultimate source of anything in our minds. In particular, we don’t know whether we ourselves are its source. This, I take it, is the main point of K 76 [a]: we don’t know how to properly distinguish between those representations, sensations, and thoughts that depend only on us and those that do not.

[b] We should say “It is thinking”, Lichtenberg writes further, as we say “It is lightning”. It ought to be highly significant that Lichtenberg, of all people, compares thoughts with flashes of lightning (Vender, ms.). He occupied Germany’s first chair for experimental physics, and among his many interests, electricity was certainly prominent. When Lichtenberg compares thoughts with lightning, he places them within a rather rich array of familiar connotations. He thinks, for instance, that strokes of lightning consist in the “forceful breakthrough of accumulated electrical matter”, just as a flood is caused by the breaking of a dam.3 He further notes that lightning is caused by electricity, and that it propagates through metal (Sudelbuch J 1636). More specifically, he knows that lightning is caused when a positively charged body comes close to a negatively charged one (Sudelbuch F 109 and F 148).4 We may thus safely assume that for Lichtenberg, lightning involves up to three subjects: the origin, the medium, and the target of a lightning bolt. By comparing thought to lightning, he is therefore suggesting that thought, too, has an origin, happens in a medium, and strikes a target.

It is tempting to look for further analogies between lightning and thinking. One might think that just as lightning happens when two electrically charged bodies are brought into contact, thought happens when two perceptions are connected. We might, for instance, spontaneously associate two impressions or ideas when they come close to one another, in some sense of “close”. Lightning might thus be analogous to association or predication.5 However, Lichtenberg does not give us much to support any such speculations.

Yet there is an interesting passage where Lichtenberg himself explains what it means to be struck by a thought (“Hogarthische Kupferstiche”, Schriften und Briefe vol. 3, 933–934):

I can happen to the best of us, in a fit of philosophical profoundness or poetic enthusiasm, especially right before mass, that they write down something that they themselves no longer understand when mass is over. However, these are strokes of genius, and strokes take no aim. Also, strokes of genius, like those of ordinary thunderstorms, in particular the cold strokes, leave no trace, neither in the element from which they came, nor in that into which they went.

Lichtenberg writes this in the context of interpreting a copper plate engraving by Hogarth, and the point of his remark is to reject the view that Hogarth himself might not have understood his own work. He concedes, as a part of this argument, that one may indeed have thoughts without understanding them. Such thoughts are like random notes scribbled down right before mass. The existence of such notes implies the existence of a person who wrote them; so this is not what Lichtenberg wants to call into question at this point. Rather, the respect in which random notes are like lightning is that they seem to have no discernible aim, and thus no meaning, and that they leave nothing behind. They are of no consequence.

Lichtenberg’s remark clearly suggests that not everything in our minds is like this. Some mental occurrences are like random notes written before mass. Others are indeed like works of art. Like Hogarth’s engravings, the latter do have a meaning, and they do leave a trace. They belong to a thinker in a deeper sense, by connecting to something in her past and having some impact on her future. These more meaningful thoughts are not like strokes of lightning.

So far, then, we have seen two things. First, by comparing thought with lightning in K 76, Lichtenberg does not deny that it happens in some sort of subject, but he leaves open whether this subject is the source, the medium, or the target of thought. When says that “I am thinking” is misleading, part of his idea is that we might not be the source, but rather only the passive medium or recipient of a thought. Second, he uses the comparison of thought and lightning in order to characterize certain mental episodes that seem to have no meaning and no significance, so that they do not seem to properly connect to other thoughts, experiences, or actions of the subject to which they occur.

2 It is Thinking

[c] After comparing thought to lightning, Lichtenberg continues: “To say ‘cogito’ is already too much, as soon as one translates this by ‘I am thinking’”. Since he began K 76 by noting that we only know that our sensations, representations, and thoughts occur, one might take his point to be the following. Instead of “I am thinking”, Descartes ought to have started with “Thought is occurring”. Taken in this way, his objection to Descartes would take thoughts to be subjectless occurrences (Russell 1967, 567; Williams 2005, 79).

On the face of it, Lichtenberg might well have had this point in mind. “There is thought” and “Thinking is going on” are perfectly fine ways of rendering the German “Es denkt”.6 Read in this way, “It is thinking” does not imply the existence of any subject, neither an “it” nor an “I”. As a consequence, Descartes’ argument will no longer appear to get off the ground. The occurrence of thought need not imply the existence of a thinker.

It is of course perfectly fine to raise the question whether thought could be a subjectless occurrence. But Lichtenberg never says that this is the question he is raising, and the context clearly suggests that he is actually raising a different question. He begins K 76 [a] by conceding that the representations we become aware of are ours. They belong to us, even if they might not depend on us. The comparison of thought with lightning in K 76 [b] does not change any of this. Lichtenberg assumes the existence of electrical bodies wherever there is electricity, presumably because he has difficulties imagining electrical discharge without a medium in which it happens. By analogy, he will have difficulties imagining a thought without a source, medium, or target.

There is, moreover, something rather odd about the idea of a subjectless thought. When Hume claims that he cannot find any such thing as a self by way of introspection, for instance, there must at least be a subject that is looking for such a self (Chisholm 1969, 10–11). And when Campbell imagines someone who is genuinely open-minded about her own existence and then is “struck by a conscious thought” (Campbell 2012, 366), it is difficult to resist asking: Who is supposed to be struck here? In both cases, the subject of thought might not be where or what one expects it to be, but it remains true that there is a subject.

Let us assume, then, that Lichtenberg does not take thinking to be a subjectless occurrence. If so, he will concede that every occurrence of thinking has some kind of subject, and the question that he directs at Descartes will be: “something, but what thing, is thinking?” (Alanen 2016, 16; my emphasis). Descartes refers to the thing in question as “I”, Lichtenberg recommends “it”.

It will be useful at this point to distinguish between two sorts of subject: (1) the implicit subject of an occurrence, and (2) the subject beyond this occurrence. The implicit subject of an occurrence is the minimal subject that it takes to make this sort of occurrence happen. It is the subject as we can know it by inference, by merely knowing of the occurrence and realizing that there must be something in which, or to which, it is occurring. It is the subject, restricted to only those features or parts that are entailed or presupposed by the occurrence itself.

The implicit subject of thought might remain very far in the background. In particular, it need not actually figure in any thought. Kit Fine (2005, 311) describes the following position:

We should not say ‘I am in pain’ but ‘it is paining’, where such a statement is taken to hold ‘egocentrically’ or relative to a subject in much the same way in which a tensed statement holds tense-logically or relative to a time. The self will be an implicit rather than an explicit subject of the first-personal facts.

The “it” in Fine’s “It is paining” does not refer to a given, manifest or explicit subject of pain, but rather marks the occurrence of pain as a first-personal fact. This first-personal fact will present itself, from the first person perspective, as lacking a subject: not as an occurrence of pain in a subject, but simply as an occurrence of pain, experienced from a certain perspective.

Fine does not deny that thoughts require subjects. When he recommends “It is paining”, as opposed to “I am in pain”, his point is that this subject is unknown to an extent that one should only refer to it by implication. Lichtenberg might be suggesting the same. Whereas “I am thinking” expresses a thought about a thinking subject, “It is thinking” expresses a thought as it is present to a thinking subject. In “It is thinking”, a subject of thought is implied but it remains implicit.

The very least that an implicit subject of thought will provide is a reference point to attribute this thought to. This is what Fine’s implicit subject does. That a thought belongs to an implicit subject means that it shares a sort of conceptual space with other thoughts that belong to the same subject. One might think that just as a substance cannot have contradictory properties, an implicit subject could not have contradictory thoughts, but this might already go too far. Thinkers can certainly contradict themselves. The point is rather that there is a distinction between one thinker contradicting another one, and one thinker contradicting herself. This distinction is only possible if thoughts are not just “out there” but rather occur in or to a subject.

The tricky part will be to assert enough, but not too much, of the implicit subject of thought. There are several ways in which a subject might extend beyond an occurrence, and thus beyond the implicit subject of this occurrence. The subject might last longer than this occurrence, that is, exist before or after it. Or it might be a subject of further occurrences and features that are logically and metaphysically independent of the occurrence in question. More generally, it might admit of any description that is logically and metaphysically independent of this one: “whatever underlies this occurrence”.

Suppose, then, that whenever thought is occurring, there must be such a thing as an implicit subject of thought (Peacocke 2012, 95; Burge 2000, 248). Under this assumption, Lichtenberg’s objection will amount to something like the following: When Descartes refers to the subject of thought in the first person singular, he has already moved beyond the implicit subject of thought. But how exactly does “I” go beyond “it”?

3 Active or Passive?

Subjects of occurrences come in two flavours: active and passive ones, agents and patients. Lightning involves both sorts of subject: something that strikes and something that is struck. By analogy, thinking might involve an agent, a patient, or both. When Lichtenberg says that some of our thoughts do not depend on us, he suggests that we are not actively performing or producing them. This might be why “I am thinking” is misleading. “It is thinking” would then be better because even if it implies the existence of an implicit subject of thought, this subject need not be the origin or active subject of thought. The implicit subject of thought might be its passive recipient, as a tree is a passive recipient of a lightning bolt. Lichtenberg suggests as much in the following note (Sudelbuch K 183):

When I write about something, the best things always occur to me in such a way that I cannot say from where.

Here, Lichtenberg receives a thought of unknown origin, so that only the passive implicit subject is known to him. Towards the end of his life, he writes (Sudelbuch L 806; see Zöller 1992, 428–429):

…if reason could set itself in motion, this would be a discovery on a par with enlarging the animals, or extending shrubs to the size of oak trees. It seems as if some kind of chance occurrence lies at the basis of all discoveries, even those one thinks one has made through some effort. To arrange the already discovered in the best order,—however, the primary leaps of invention seem as little to be the work of deliberation as the movement of the heart.…

What I said on another occasion belongs here, that one should not say “I am thinking”, but “It is thinking”, as one says “It is lightning”.

Here, Lichtenberg himself is telling us what his point is. He regrets that reason cannot set itself in motion, but he seems to think of this as something that could be fixed. There might be ways, after all, of growing shrubs to the size of oak trees (Sudelbuch L 789). In any case, there are many occasions where the mind is passive, rather than active, and where the driving force is really some sort of chance occurrence (Sudelbuch H 150; Zöller 1992, 424). In the above passage, Lichtenberg compares such accidental and passive actualizations of reason with the movements of our heart. These movements happen in us, we are their subject. However, they are beyond our immediate control. In this sense, we are passive with respect to them. If this is Lichtenberg’s point, it is not simply that we are passive recipients of our thoughts. We are not simply passive recipients of our heartbeats. Rather, our heart belongs to us, and it belongs to our life that our hearts beat, spontaneously and autonomously, within us. If our thinking is like our heartbeat, the question is not whether we produce our thoughts or receive them from an outside source. The suggestion is rather that some part of ourselves is thinking them, such that we have little direct control over this process.

More than 25 years earlier, Lichtenberg had similarly compared thinking to growth and digestion (Sudelbuch A 130):

We think early enough, but we don’t know that we think, as little as we know that we grow or digest.

When we digest or grow, there is a clear sense in which we are doing it, but there is also a sense in which we are passive. We have no immediate control over our digestion and our growth. If we are passive towards (some of) our thoughts in the same sense, this will not mean that we aren’t thinking them. It will mean that we have no or only limited control over them.

Zöller says that Lichtenberg demotes the subject of thought to the status of a mere observer (1992, 429), but in light of the passages discussed so far, “observation” seems too disengaged. The passive subject of a stroke of lightning is certainly not merely an observer of the stroke. Also, we are not mere observers of our heartbeat and digestion. Both belong to our life, but there is a sense in which they are beyond our control.

There might be an argument to the effect that no subject of thought can possibly be passive with respect to all of its thoughts. Burge, for one, presents such an argument, and he turns it against Lichtenberg (Burge 2000, 251):

Here we see a point about agency that Lichtenberg missed in comparing thinking to lightning’s occurring. Thinking is necessarily associated with reasoning—thinking guided by reasons—and reasoning cannot in general be a mere ‘going on’. In making inferences, a being is ipso facto an agent.

Lichtenberg might very well have missed this. Note, however, that he never actually claims that we are passive with respect to all our thoughts. He claims, more specifically, that we are passive with respect to some of our thoughts, and he suggests that one of the thoughts we are passive towards might be Descartes’ cogito.7 A specific argument will be required, then, to show that Descartes’ cogito, in particular, cannot be a mere “going on”.
At any rate, Lichtenberg is pointing to something in our minds that is neither the kind of active, critical thought that Burge has in mind, which has the power to immediately shape our other thoughts and actions; nor is it the kind of “going on” that we merely observe in ourselves. This is something that Burge seems to have missed on his part, when he relies on the assumption that every thought requires an agent (Burge 2000, 269):

Where one’s seeming understanding of an apparent assertion is accompanied by an awareness that one is not the agent of the assertion, one has an apriori prima-facie ground for presuming that there is another mind, another rational agent.

Burge is here implicitly assuming that a thought of which I am the passive subject must be the thought of another agent. We have seen that Zöller relies on the same distinction: If a thought is not of our making, we must be merely observing it. I suppose Freud followed the same pattern, when he raised the “it” (“id” in the English translation) to the level of an autonomous agent.

Lichtenberg, in contrast, is more cautious, more attentive to the phenomenology of thought. We might not really know what to say about thoughts that seem to strike us from out of nowhere, but it is certainly imprudent to rule out their possibility, to deny that they are thoughts, or to postulate an unknown, separate agent who must have been actively thinking them. One might grow a beard without actively doing anything, but this need not imply that someone else is doing it. By the same token, one might be the passive subject of a thought, and this need not imply that someone else is its active subject.

There are, then, at least the following three ways of making Lichtenberg’s point. First, the occurrence of a thought might have no implications whatsoever concerning the existence of anything like a subject of thought. Second, even if it did imply the existence of a subject, this subject need not be more than an implicit subject of thought, and addressing it in the first person singular might go beyond that. Third, more specifically, it might be misleading to portray it as the active subject of thought.

4 The Principia Version of the Cogito

Let us now look at the cogito argument, as Descartes presents it in his Principia. Everyone knows this argument, so I will only highlight a couple of things. Descartes argues, in the first person, that as long as I am doubting, I am thinking, so that I cannot possibly be doubting that I am thinking. This is how he summarizes this argument (Principia I 7, AT VIIIA 7; tr. CSM, modified):

Accordingly this piece of knowledge—I am thinking, therefore I am (ego cogito, ergo sum)—is the first and most certain of all to occur to anyone who philosophizes in an orderly way.

Two minor notes about this passage. First, Descartes states the conclusion of the cogito as “I am” (sum), as opposed to “I exist” (existo). In other contexts, he uses sum and existo interchangeably. In the Latin version of the Discours, as well as in the Second Meditation, Descartes uses both verbs: sum, sive existo (AT VI 558; VII 25; VII 27). This will be relevant later on.

Second, Descartes literally says that the cogito argument itself must occur to us (occurrat). He does suggest that it occurs to anyone who has previously been an active subject of certain thoughts. But this one most important thought, the cogito itself, is actually introduced as a thought of which we are a passive subject.

This is very much in line with the situation in which I, the meditator, find myself in the Second Meditation. I am imagining an evil demon who is trying to put the thought into my head that I don’t exist. I start out at the receiving end, but there is no reason to doubt that what is passive here is a subject, properly addressed in the first person. This is because there never was a time in the Meditations when the meditator was, or could have been, confronted with anything like a subjectless thought. The first thing Descartes concludes in the Second Meditation is: “I must be something” (AT VII 24). The second thing he concludes is that he must be thinking (AT VII 27). There is thus no reason why Descartes should ever have said “It is thinking”, if one takes this to refer to a subjectless occurrence. Let me now return to the Principia.

After presenting the cogito argument, Descartes adds a definition of thought. This definition is of particular importance, because the nature of thought will have implications for the limits of the implicit subject of thought. Here it is (Principia I 9, AT VIIIA 7; tr. CSM, modified):

By the term ‘thought’, I understand all things that happen in us while we are conscious of them, insofar as there is consciousness of them in us.8

This definition says four things. (1) Thought is something that happens, and (2) when it happens, it happens in us. Further, (3) thoughts are objects of consciousness, and (4) they are thoughts only insofar as they are objects of consciousness.9 In the context of Lichtenberg’s objection, the first two points are rather remarkable. Descartes is not actually saying here that we perform or make all of our thoughts. He says that thoughts happen in us, as he had said earlier on that the cogito argument occurs to us. This leaves open whether we are their active or their passive subjects.

As for the other two points, we will be able to make a lot of progress by taking a closer look at a peculiar logical device that Descartes uses in his definition of thought: he stipulates that what is happening in us is a thought insofar as there is consciousness of it in us. This locution, “insofar as”, might seem rather harmless to us, if somewhat obscure. It is important to note, however, that the intellectual tradition that Descartes grew up with offered elaborate theories on how “insofar as” works. (Bäck 1996).10 These theories go back to Aristotle, who often makes a point of distinguishing between two ways of identifying a thing: simpliciter (ἁπλῶς) or with qualification. In De Generatione et Corruptione I 2–3, for instance, Aristotle makes a lot of the distinction between qualified and unqualified coming to be. Let me explain this in a separate section.

5 Qua-Objects

When a tomato comes into existence, it comes to be, period. When a tomato comes to be red, its coming to be is qualified by the qualifier “red”. Aristotle introduces the distinction between qualified and unqualified being because the Greek language has no separate word for existence. This makes existence claims look like shorter versions of predications: “The tomato is”, period; as opposed to “The tomato is red”. Together with other features of Greek grammar, this makes for an odd way in which Aristotle can say that when a tomato comes to be red, there is something that ipso facto comes into existence. That which comes to exist when a tomato comes to be red, is the tomato-qua-red. Aristotle does not distinguish between “The tomato comes to be red” and “The tomato-qua-red comes to be”.11

So there is a thing that comes to be when a tomato comes to be red. Let us call this thing a romato. Romatoes are qua-objects: they are tomatoes qua red. They differ in a couple of interesting ways from plain tomatoes. For instance, they have a shorter life span. A romato comes to be when a tomato turns red, and it ceases to be when this tomato ceases to be red. This will further imply, for instance, that the minimum size of romatoes differs from the minimum size of tomatoes, given that tomatoes do not turn red before they have reached a certain size. Moreover, romatoes will have certain essential features that tomatoes lack. They are, for instance, necessarily red.

Romatoes may seem to be very odd creatures. There are many rather ordinary things, however, that are almost as odd as romatoes, and many of these things happen to overlap with humans. There are, for instance, students. In a sense, a student comes to be when a human starts going to school. When we say how old a student is, we state the age of the underlying human, but we also speak of freshmen and fourth graders. Students have certain essential properties, and being human is not actually among these. If martians were to send their kids to one of our schools, martians might well be students. Another rather interesting case are passengers. People are passengers as long and insofar as they are using certain means of transport. But non-human things might count as passengers, too, e.g. when a cellist books a seat for her instrument. Judging from an entry in a passenger list, one might not be able to tell whether a seat is occupied by a human, a martian, or a cello. Further, as Anil Gupta points out, passengers are not counted in the same way as traveling humans are (1980, 23). When one human being uses an airline twice, they are counted twice. The same is true for presidents: Grover Cleveland was both the twenty-second and the twenty-fourth president of the United States, so that the number of presidents is not the number of humans who held this office (Cohen 2008, 5).12

6 The Thinking Thing

All this might seem to have led us far away from Descartes, but it is in fact extremely important and significant for the Principia version of the cogito. When Descartes defines thought as what happens in us insofar as it is the object of our consciousness, he introduces thought as a qua-occurrence. We know that for some time and in some respect, what is happening in us is an object of our consciousness, which makes it a thought. But we cannot know what, if anything, might have been true of this occurrence before we became conscious of it, nor can we know whether there are respects in which it is not an object of consciousness. This is how qua-entities work. If thoughts are qua-occurrences, we do not know what our thoughts are like insofar as we are not conscious of them. For all we know, they might be physical processes, they might make a sound, and they might last forever. Or not. Descartes is being extremely careful here. He is not committing to anything that might go beyond the claim that in some respect, whatever I am going through when I am doubting my own existence must be a thought.

This suggestion, that there might be respects in which we are not conscious of our thoughts, might seem to contradict Descartes’ official doctrine. However, there are in fact many ways in which Descartes admits of something unconscious in our minds (Simmons 2012, 10–13). For instance, he concedes that we may not be aware of certain relational facts about our own thoughts, namely that and how some of them are actually tied to the body (AT VII 219). Further, in a curious passage in the Discours, Descartes says that one might be thinking something without being aware of doing so (AT VI 23). And in a letter to Mersenne, he says that he has never claimed that we have control over all our thoughts (AT III 249). Moreover, he says that we can have a clear and distinct idea of something that we don’t comprehend (AT VII 46). These passages suggest that even if there can be no thoughts of which we are not at all conscious, there may be many things about our thoughts that we are not conscious of. We are conscious of our thoughts under a description, so that there may well be other descriptions of the same, such that we are not conscious of what we are doing under those other descriptions.

So far, we have determined two things. First, nothing in Descartes’ definition of thought prevents that our thoughts merely occur to us, as opposed to being produced or performed by us. We may very well be passive subject of our thoughts. Second, Descartes defines thoughts as qua-occurrences. As such, thoughts might relate to partly unconscious occurrences in the same way in which romatoes relate to tomatoes. That is, the occurrences that are thoughts insofar as we are conscious of them might be any number of other sorts of things insofar as we are not conscious of them. When we know that we are thinking, without knowing anything else, we might well be looking at the tip of an iceberg. At least initially, Descartes allows for all this.

As for Lichtenberg’s point, it is now important to note that just as a thought is a qua-occurrence, its implicit subject will be a qua-object (or a qua-subject for that matter).13 In the initial stages of the cogito argument, we know what is happening exclusively insofar as we are conscious of it. Whatever else it may be, we know it only as a thought. Likewise, we know the subject of what is happening exclusively insofar as it is a subject of thought.14 This is why Descartes refers to it as a thinking thing (res cogitans), as opposed to a thinking human.

Note that the Latin res is rather flexible. In Latin, as in English, pretty much anything can be “a thing”. That people have a res may mean that they have a romantic relationship, and the res publica is clearly not a dry, middle sized object. In Descartes, the notion of a thing (res) is closely connected to the notion of reality (realitas) and real distinction (distinctio realis). The realitas of a thing is what it is, and that two things are realiter distinct means that what one thing is is not what the other is. When Descartes declares that mind and body are really (realiter) distinct, and when he refers to both of them as res, all he should be taken to say is that what the mind is is not what the body is, and that for each of them, there is such a thing as what they are. But of course, what I am and what you are can be the same, although we differ in number, and what I used to be can differ from what I am now, although I am still numerically the same. That the mind is one “thing” and the body another does not imply that they differ in number.

Again, Descartes is being cautious. We know the subject of thinking only under one description. It remains to be determined whether this description is the only one that applies, and if not, how it relates to other possible descriptions of the same. By the end of the Second Mediation, the meditator does not know whether she is numerically distinct from a bodily being.

Modern commentators tend to apply Leibniz’s principle of the distinctness of discernibles in this context, arguing that if the essence of the mind is not the essence of the body, mind and body must differ in number (Almog 2002, 5 and 99). However, if we are indeed talking about qua-objects here, not even Leibniz himself would make such a move (Hennig 2011, 153). It is easy to see why: A tomato qua red and this tomato qua round are different qua-objects, but they are in fact one in number. So at this point the meditator has no reason to be a dualist: she does not know whether mind and body are one or two in number.

Descartes, to be sure, tells us that we can count whenever we draw a distinction (Principia I 60, AT VIIIA 28). So there is, for Descartes, a sense in which humans are two: each human is (1) a mind and (2) a body. But this applies to all distinctions, including modal and conceptual ones. There is a sense in which everything is as many things as there are respects in which it may be thought of. In this sense, a red tomato is at least two things: a tomato and a romato; but of course, a red tomato is not really two things in number. What Descartes establishes in the Meditations is not a numerical distinction in the robust sense in which a table is numerically distinct from a chair. Rather, he is “aiming from the start to establish a distinction in kind” (Hatfield 2014, 256).15

The idea that mind and body may differ without being numerically distinct might seem to turn them into properties or modes. This is, presumably, because we can easily see how two different features or modes may belong to numerically one thing. It is important, however, to notice that the same move works without the assumption that mind and body are properties, features, or modes. “Two” qua-objects may differ without differing in number, but qua-objects are indeed objects. A romato is not a property, feature, or mode of a tomato, it is a red tomato. In the same sense, the implicit subject of thought can be a thing while being a qua-object.

7 I am Insofar as I am Thinking

Let us grant, then, that there is a minimal interpretation in which “I am thinking” must be true, even according to Lichtenberg, while I am doubting my own existence. In this interpretation, “I am thinking” asserts that a qua-occurrence is happening in an (active or passive) implicit subject. Once we do this, Descartes’ existence claim follows immediately. The move is the same as the one we made above for tomatoes and romatoes. When a tomato is red, a romato exists. By the same token, when I am thinking, I-qua-thinking exist:

I am thinking → I am qua thinking → I-qua-thinking am.

This sequence explains why Descartes can use sum and existo interchangeably. For every occurrence of esse can be replaced by a construction involving existere:

A est B ↔ A qua B existit.

What the cogito argument shows is the existence of a qua-object. We know of its existence only as long as it is thinking, and only insofar as it is thinking. We do not know whether it existed before or after the present occurrence of thought, and we do not know whether it does anything other than thinking. For all we know, it might be made up of Swiss cheese or a heap of grand pianos.

It might help to compare the implicit subject of thought with what Marc Cohen has called a simple kooky object (2008, 13). Cohen begins with the notion of a kooky object. Romatoes are kooky objects, and so are presidents, passengers, and students. These things are all things-in-respects. They consist, as it were, of a thing and a feature. A simple kooky object is like a thing in a respect minus the thing. Instead of considering my daughter as a student, for instance, we may focus on the respect in isolation, namely the student as such. This should not be confused with focusing on abstract properties. We are not focusing on studentship, we are focusing on a student, one particular student in fact, merely and precisely insofar as she is a student. This is obviously what Descartes is asking us to do: to focus on a thinker, ourselves, merely and precisely insofar as we are thinking. Implicit subjects are simple kooky objects, and Descartes’ res cogitans is one of them.

This is, at least, the immediate result of the cogito, as it is reached in Principia I 8 and by the end of the Second Meditation. In his Synopsis of the Meditations, Descartes emphasizes that this result is quite limited. For instance, it does not amount to a proof of the immortality of the soul (AT VII 12–13; tr. CSM):

…since some people may perhaps expect arguments for the immortality of the soul in this section, I think they should be warned here and now that I have tried not to put down anything which I could not properly demonstrate.16

All he could properly demonstrate is the existence of a qua-object.

8 Deus ex machina

Had Descartes never drawn any further conclusions from his initial result, we might characterize his view as a dual aspect theory. For supposing there are mental and bodily phenomena, everything that we have considered so far points towards the idea that thinking things are things insofar as they are subject to mental phenomena, and bodily things are things insofar as they are extended. Nothing so far prevents that in fact thinking things and bodily things are the same, in the way in which a student can be a passenger, because both are the same human being.

Now of course, Descartes will eventually conclude that the mind is an immortal and immaterial substance. We cannot simply ignore this, and it seems incompatible with a dual aspect theory.

It might thus appear as though we have attempted to straighten an argumentative carpet, but only moved the bump in it. To some people, such as Russell, it looks like Descartes commits an obvious mistake right in the beginning of his argument, which ultimately leads to his substance dualism. I have been defending his initial steps, by arguing that they are not affected by most versions of Lichtenberg’s objection. Up to a certain point, Descartes is perfectly right. Still, if dualism is wrong, there must be some mistake later on.

I do think, however, that we have made considerable progress: We have moved the bump in the carpet to exactly the point where it belongs. Descartes himself marks this point in a rather clear way. It is the point in his argument where he appeals to divine intervention.

Descartes believes that he can prove the existence of God as a corollary to the cogito argument. My preferred reconstruction of his argument goes roughly as follows. All thinking is subject to certain objective criteria of truth, consistency, and adequacy, so that whenever thinking is going on, such criteria must be available and applicable. Further, we cannot make up such criteria as we are thinking, so in this sense, they must have a “higher status” than the thoughts they apply to. Now Descartes thinks that there can be such criteria only if there is a being that perfectly satisfies them. This is the God that Augustine identifies with the Truth (Menn 1998, 151 and 281).

There is a sense in which this argument shows something important. Trouble begins, I think, when Descartes argues that mind and body are separable because God can separate them. Descartes needs to say this because he knows that all he could show otherwise is only that the soul does not necessarily have to perish when the body decays. As he says in the Synopsis, there is no proof that the soul must survive after death, only an argument to the effect that God will be able to preserve it (AT VII 14).

But isn’t the mere assumption that God might separate a mind from a body incompatible with a dual aspect theory? I do not think so. It is not actually difficult to understand what it would take to separate a mind from a body. There is a very easy way of doing this: make a human stop thinking, and you will have a human body without a mind. With the right kind of machinery, one may be able to keep this body alive for a long time. What God can do is simply the converse. Instead of making a body stop thinking, God can make a thinker stop being extended in space. Stated at this level of abstraction, it is pretty clear what is going on. On a more concrete level, of course, a thinker without a body is more difficult to imagine, like a smile without a Cheshire cat. And this means that from this point on, Descartes is actually in trouble.17

At the same time, however, the point where trouble begins is exactly the point where we no longer need to follow Descartes. We can stop following Descartes because he is aiming at a conclusion that should no longer interest us. For the question that Descartes answers by appealing to divine intervention is actually the following one: “What happens to human beings in between death and resurrection?” And there is only one reason why it might be important for a thinker to persist in between death and resurrection: God will punish and reward every single one of us. To this end, God needs to make sure that I survive after death, without my body, yet as this particular mind, as opposed to another one. We should no longer attempt to show how God can do this. And this means that we can abandon Descartes’ line of argument at exactly the point where his God starts doing real work.

Note further that the very idea that we might find difficult to grasp here, the idea of a thinker in the absence of a human being, is remarkably similar to the idea that many have found in Lichtenberg, assuming that it is directed against Descartes. It is the idea that there can be thinking without an observable subject of thought. Descartes is trying to show that there can be thought, a qua-occurrence, and a thinker, a qua-object, without the physical environment in which they usually occur. This is like trying to show that there can be students, passengers, or students that are literally nothing other than this: students, passengers, presidents. And this, in turn, is rather similar to trying to show that there can be an episode of thinking without a thinker.

9 Conclusion

I have distinguished three versions of Lichtenberg’s point. First, “It is thinking” might suggest that a subjectless episode of thinking is occurring. Second, the point might be that the subject of thought is merely an implicit subject of thought, and not a full blown person, as the first person pronoun might suggest. Third, it might be that the subject of a thought need not be the source that produced or performed it. As far as Lichtenberg is concerned, I have set the first interpretation aside. What Lichtenberg wants to suggest, I take it, is that the mind need not be the active subject of the thoughts that occur to it. The occurrence of thought merely implies the existence of an implicit subject of thought, which might be its source, its medium, or its passive recipient. When Lichtenberg compares thought with lightning, his point is that at least in some cases, we seem to be the medium or target of our thoughts rather than their source. He further suggests that in such cases, our thoughts take no aim and are of no consequence. Conversely, he associates active thinking with an ability to make sense of one’s thoughts and to integrate them into one’s life.

Descartes, on the other hand, does not actually suggest that we are the active subjects of all our thoughts. He defines thought as something of which we might be either an active or a passive subject. Further, he is very careful to remain within the limits of the implicit subject of the cogito. He neither assumes nor denies that the thinking thing is anything other than thinking. He does this, in particular, by employing the locution “insofar as”, which makes it possible to state his existence proof as follows: “I am thinking” implies “I-qua-thinking am”.

With respect to Descartes, I have distinguished between one part of his argument that I take to be perfectly valid and unaffected by Lichtenberg’s point, and another part, which I take to be both problematic and unnecessary. Both features of the latter part are closely associated with Descartes’ appeal to God. First, the only way he can show that the mind can be a separate entity is by appeal to God’s ability to eventually separate it from everything else. Second, the only reason why he wants to show this is a religious one: God needs to separate our minds from our bodies in order to be able to maintain our individuality in between death and resurrection. For both reasons, we no longer need to follow Descartes all the way. For our purposes, we can take the cogito argument to imply the existence of a qua-object: something, whatever it may be, that is currently a source, a medium, or a target of a thought.


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Translations from Lichtenberg are my own. I follow Tester (2013, 336 n. 1) in moving the comma in the first sentence of K 76, which otherwise would have read: “…others believe we at least depend on us; where is the boundary?” I have divided K 76 into four sections, [a]–[d], for convenience.

“It is lightning” hardly is proper English, but it is important to preserve three features of the original: “Es blitzt” refers to (1) an ongoing occurrence of (2) lightning, as opposed to thunder, and (3) Lichtenberg uses a potentially impersonal construction, akin to “It is raining”.


The last sentence, K 76 [d], is in many respects the most interesting and important one, but I will not attempt to say anything about it in the present context. It would take too much time.


“Über die Aërostatischen Maschinen”, Schriften und Briefe vol. 3, 69.


Lichtenberg actually introduced “+” and “−” as labels for the two kinds of electrical charge. See “Von einer neuen Art, die Natur und Bewegung der elektrischen Materie zu erforschen”, Schriften und Briefe vol. 3, 30; see also Kommentar zu Band 3, 12.


It is rather unlikely that Lichtenberg would have taken thoughts to actually be caused by electrical discharge. He was aware of Luigi Galvani’s discovery, published in 1791, that the legs of a frog twitch when they are exposed to electricity (Sudelbuch J 1980; Letter to Blumenbach, Oct 5th 1792, Schriften und Briefe vol. 4, 825). These findings were controversial, however, and in addition to accepting them, Lichtenberg would have had to assume that thoughts are brain processes, and that all brain processes are sufficiently similar to what happens in a frog’s nerves.


In certain German dialects, it is even possible to say “It has mountains” for “There are mountains” (Grimm’s Wörterbuch s.v. “Haben”, vol. 10, 68–69).


Note that Descartes denies that the cogito is an inference (AT VII 140), so Burge’s argument does not necessarily apply in this instance.


Cogitationis nomine, intelligo illa omnia, quae nobis consciis in nobis fiunt, quatenùs eorum in nobis conscientia est.


If all thoughts are the object of consciousness, and if consciousness itself is a further thought, a regress will result. Simmons therefore argues that “Cartesian consciousness … is a kind of reflexive cognition that every thought has of itself” (2012, 8). However, as much as this might be a reasonable way out of a pressing dilemma, there is at least one reason why it won’t work for Descartes: Descartes invariably attributes consciousness to the thinker of a thought, and never to the thought itself (Hennig 2006, 77).


I recommend Bäck for an overview over these debates. I am not quite satisfied with the way he reduces aspects of things to parts of them. See also Hennig 2011.


Romatoes, students, passengers, and presidents are instances of what has been called phase sortals. Alan Code therefore suggests construing Aristotle’s qua-objects as intersections of space-time worms (1976, 171). Seen in this way, the current president of the United States is an unlikely coincidence of an entity that used to have black skin with an entity that used to have yellow hair. I suspect that this simplifies things too much, because space and time are not the only dimensions along which things may be differentiated. I might be a passenger throughout my entire life, so that the person and the passenger that I am are located in the exact same places at the exact same times. There might not even be a possible world where this is not so. Still, there will be a difference between me qua person and me qua passenger.


Carriero reads Descartes in this way (2009, 89–90).


Or, as Brown puts it, a “minimal self” (2014, 245).


Brown, I take it, has something similar in mind when she distinguishes two questions:

“The answer to the ‘What is this (union)?’ question is: two substances, mind and body. The answer to the ‘Who is this?’ question is: a single person” (2014, 249). The What-­question is one about the (two) kinds of things involved, whereas the Who-question is about numerically one individual.


See also Descartes’ comment on his use of “praecise tantum”: AT IXa 215; Cottingham 1992, 243; Carriero 2009, 94–97.


Descartes wants to avoid attributing miracles to God (Le Monde, AT II 47–48), so even if the maintenance of a soul without a body requires God’s help, it must be a perfectly natural thing to occur. In this sense, “God need not be mentioned here” (Hatfield 2014, 259). But in another sense, God does need to be mentioned: even though we have reason to expect the soul to survive, we have no proof.

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