If an alien could talk

1. Wittgenstein's contention

Ludwig Wittgenstein contended that "If a lion could talk, we wouldn't be able to understand it" (Philosophical Investigations, Philosophy of Psychology - A Fragment (formerly known as Part II), section xi, page 235, paragraph 327).

For some earlier thoughts on this topic see Baron, "If a Lion Could Talk, We Could Not Understand Him". Here we shall go beyond lions to consider communication with aliens. The example will be communication between the human Ryland Grace and the alien Rocky in Andy Weir's novel Project Hail Mary. We shall base our comments on the novel, not on the 2026 film.

2. The challenge of communication

Ryland Grace and Rocky are both visiting a distant solar system, searching for something that will counter the microbe that is draining energy from their home stars. Ryland knows more physics, but Rocky has great engineering skills and access to a material of remarkable strength and versatility. In a hostile environment, they need each other. Rocky's skill in building isolated spaces and airlocks gets over the problem that each needs an environment that would kill the other - different temperatures and atmospheres. But even after they have come face to face (through a transparent and sound-conducting screen), they find that they have no language in common. Ryland speaks English. Rocky uses sounds that Ryland records as sequences of musical notes.

Two practical problems are solved in ways that are perfectly straightforward.

The first problem is that most human beings are not well enough attuned to the details of sequences of musical notes to build a large and stable vocabulary that way. Ryland uses a computer to record and analyse the sequences, and to build up a dictionary. Rocky may be presumed to have some corresponding method, although his mental powers mean that he would have no need for an external device. Indeed, his species do not have computers.

The second problem is that Rocky cannot see Ryland's gestures in the ordinary way. Members of Rocky's species do not sense light, but instead use sound transmission and reflection to build up internal models of the world that are quite as refined as sighted human beings construct using their eyes. One might ask how this could be so, given that sound waves have much longer wavelength so that their portrayal of the world would be less refined, but we can let that pass. One could for example take sound inputs from many angles and compute details of the world that way. One might also be concerned that the internal models would be structured differently from those built up by sighted human beings. That would however not matter so long as they had comparable information content.

Solutions to such practical problems do however leave us with the big problem of getting communication going when languages are completely different. How could that be achieved?

3. Getting communication going

3.1 The challenge

The challenge of establishing communication between beings that have no language in common has attracted considerable attention. A significant contribution of philosophers has been to set up the problem as one of radical translation between languages and to add the problem of radical interpretation, that is, making sense of the speakers of an unknown language by attributing mental states to them. Philosophers and others have gone on to consider how the challenge might be met.

The foundational figures in this line of enquiry are W. V. O. Quine and Donald Davidson. They both argued for the importance of the principle of charity, the gist of which is that we should try to interpret an unknown language in such a way as to lead us to see its speakers as mostly telling the truth and mostly getting things right.

If Ryland and Rocky started by trying to interact at the level of general conversation, the principle of charity would not be much help. The lives of beings from different planets, with different physical environments and sensory apparatus, would be too different for Ryland to have much sense of what truths to try to match up with Rocky's utterances.

Fortunately for Ryland, and for the plausibility of the novel, general conversation is not where the characters start. Ryland and Rocky have specific practical problems to solve, and the territory of their discourse is physics, chemistry, and engineering. Over this territory, Ryland can look in Rocky's discourse for utterances to match up with truths that are already known to Ryland.

This is not all there is to it. We must say rather more in order to make the novel plausible. But what must be added differs as between physics and chemistry on the one hand, and engineering on the other. We shall now look at each in turn.

3.2 Physics and chemistry

Physics and chemistry are, so far as we can tell, the same throughout the Universe except perhaps in certain extreme environments within which nothing elaborate enough to be either alive or conscious could endure anyway. Ryland brings considerable knowledge of these disciplines to bear, more extensive than Rocky has. For example, Rocky is unaware of relativistic effects like time dilation, and his society has not got as far as developing computers.

When thinking about the novel, the specific form of the difference in stage of development does allow us to put to one side the problem of different but equally sophisticated conceptualisations of the natural sciences. The form in question is that Rocky's science can be regarded as an earlier version of Ryland's. Given this, we can see Ryland as assuming that Rocky is expressing scientific truths, or what human beings would have regarded as scientific truths in earlier centuries. Ryland can then apply the principle of charity to make sense of what Rocky says.

We should however note in general the problem of different conceptualisations. We cannot rule out the possibility of radically different ways of doing physics or chemistry that would have made it very hard for Ryland to find truths to match up with Rocky's utterances. 

The best response to the problem of different conceptualisations might be to shift from a theoretical understanding of the world to the level at which empirical results were evident. Rather than describing what was really going on according to a given conceptualisation of physics or chemistry, we would describe perceptible procedures and their outcomes. We could then add a classification of procedures to identify those that we saw as measuring the same kind of thing - for example, rotation or temperature - and a classification of results to identify those that we regarded as related by being about the same kinds of objects, or by having analogous mathematical structures (such as linear relationships between variables).

This move to classification of the perceptible would be far from free of problems. A physics or chemistry that amounted to the classification of procedures and observations, without an underlying theory that explained the classifications, would be greatly impoverished. We might also find that different theories, possessed separately by Ryland and Rocky, would encourage different classifications. And differences of sensory apparatus might make it hard for there to be commonality even of empirical results, unless they were described in terms that were at some distance from the mere contents of perceptions - and therefore in terms that had at least some theoretical dependence, although not dependence on deep physical and chemical theory.

Despite these difficulties, we can still speculate that if there had been insufficient overlap of scientific theory, Ryland could have fallen back on looking for truths as to how to achieve practical goals, truths that he could have matched up with Rocky's utterances. There was in any case enough commonality of practical goals because both characters were on the same mission, to find an antidote to the organism that was sucking the energy out of their home stars. That goal was the same, and it implied the subsidiary goal of survival, also the same for both characters.

Such a restriction to interpretation based on common practical goals was not in fact imposed on the characters. But those practical goals were central to the story, and successful interpretation was needed in respect of both the goals and ways to achieve them. This brings us on to the field of engineering.

3.3 Engineering

The goals to be achieved by the engineering that is described in the book are ones that it is hard to think would be conceived in some other way that would be so different as to impede the development of communication. These goals include allowing Rocky and Ryland to stay in their own very different atmospheres on Ryland's spaceship, building a chain that will allow a collection device to be lowered into a planet's atmosphere, and manoevering the spaceship by repurposing small spaceships that had been provided to take material back to Earth.

Engineering does depend on physics and chemistry, and those sciences could still be subject to radically different conceptualisations. But the move to practical goals should make the differences fall away. One way to look at this would be so say that so long as there were shared types of goal, practical engineering would be realisable in the same way on top of multiple conceptualisations of physics and chemistry. Realisability in the same way would not extend to the theory of engineering, but that would not have mattered for Ryland and Rocky. Their practical goals were the same, and they were focused on practical engineering. Rocky did have a material, called xenonite, that was unknown to Ryland, but its useful property of enormous strength could easily be fitted into Ryland's conceptual scheme.

4. The next steps

We can see how Ryland and Rocky might build up communication on matters of science and engineering. But they go further. Rocky grasps human concepts such as those of sadness and sarcasm, or at least identifies concepts from his form of life that correspond to them well enough. And by the end of the novel, Ryland and Rocky are perfectly fluent in the comprehension of each other's languages. To speak Rocky's language, Ryland has to use a special musical instrument that generates the necessary sounds. But that does not represent a lack of linguistic ability, any more than would the need to use hands rather than tongue to communicate with deaf people in a sign language.

How could this degree of communication be achieved, given that the common ground of physics, chemistry and engineering was not there to support it once one moved from life as analysed scientifically to life as experienced from the inside?

We may assume that there is something in alien life corresponding to desire, and something corresponding to discomfort, where the alien versions would at a minimum have in common with the human ones that they would provide the subject with grounds for action, whether action to satisfy a desire or action to end a discomfort. Indeed, the novel assumes that much commonality. Both Ryland and Rocky have goals and are aware of what would or would not be adverse for themselves.

One could word desire and aversion in purely biological and mechanically psychological terms. An automatic vacuum cleaner can wander about a room, pursuing a goal of reaching every part and using sensors to avoid colliding with obstructions. But a big move up, available both to Ryland and to Rocky, comes with self-consciousness, an awareness that these are one's own goals and aversions, that one ought to act accordingly, and that one could choose to act differently. There is something special about a conscious imperative, conceived as an imperative to oneself and not merely conceived impersonally as a program that the organism will follow.

Once one has that crucial step in place, it is perfectly possible that one could have enough common ground with an alien species (or indeed with Wittgenstein's talking lion) to identify some of one's own concepts with some concepts in the other creature's vocabulary. The identifications would be imperfect, and considerably more so than the imperfect identifications that we make across human languages, such as happiness and bonheur, or cosiness and hygge. The imperfection in those linguistic examples reminds us that concepts like these only get their full meanings from the whole cultures in which they are embedded. And the same would be true in a more dramatic way, leading to greater imperfection of identifications, as between human and alien cultures. But imperfect identifications could still be enough to sustain conversation, albeit with occasional misunderstandings.

Finally, there is the possibility of going native. If a human being were to take up permanent residence in an alien culture, he or she could in due course come to adjust cultural expectations and ways of viewing the world and other conscious beings, until eventually he or she would be fully absorbed and there would be no question of how to identify concepts in the new culture with concepts in the old one.

References

Baron, Richard. "If a Lion Could Talk, We Could Not Understand Him". Ethical Record, volume 111, number 4, May 2006, pages 9-12. https://rbphilo.com/baron-richard-if-a-lion-could-talk.pdf

Weir, Andy. Project Hail Mary. London, Penguin, 2022 (first published in 2021).

Wittgenstein, Ludwig. Philosophical Investigations, revised fourth edition. Oxford, Blackwell, 2009.