My friends and I were sitting on the deck one Summer afternoon sipping cokes by the pool while discussing different philosophical matters. It was a hot day, and I was introducing Descartes’ philosophy to them—as any normal person in an everyday conversation does—and explaining why it was important and what it meant for us. I set 
it up like this: He asked if his whole life were an illusion, a dream, and if there were an Evil Demon that was deceiving him, causing his senses to be misleading. It is impossible, I explained, to distinguish between waking reality and a dream, according to Descartes. However, searching for a first principle, a single starting point of knowledge from which to start, he realized he had been thinking this whole time. The process of questioning whether he was in a dream presupposed that there was a questioner who was doing it. This led him to remark, “Cogito, ergo sum,” or “I think, therefore I am.” By doubting all his senses, he was led to the conviction that he could not doubt that he was doubting in the first place; for otherwise, he would not be able to doubt: He would have to exist first before he could be deluded.
After hearing this, my friends seemed pretty convinced, and pondered it a bit. Out of nowhere, one of them said, “Well, babies aren’t self-conscious.” A pause. “So do babies exist?” Taken aback, unprepared for such a response, I readily dismissed the notion, called it absurd, and tried to think of an answer. We began debating whether or not babies knew they existed, or whether they could even think about thinking. Of course, the question itself—do babies exist since they are not self-conscious?—is actually grounded in a misunderstanding: Descartes was not trying to prove his existence; rather, he was trying to prove he had certainty, something undoubtedly true. But for the sake of argument, we entertained the idea. Common face shouts till it is red in the face, “Obviously, yes, babies exist! Only a madman would doubt their existence. I mean, we see them right in front of us—they’re right there, they exist!”[1]
This prompts the question: If we are conscious of a baby existing, yet they themselves are not conscious of themselves existing, do they exist? Babies are fascinating creatures. They are copies of us, miniature humans who must learn to cope with and understand the world in which they are living through trial-and-error. Seeing as they are capable of such amazing cognitive feats like cause-and-effect and language acquisition, investigating their conscious abilities sounded intriguing. A delve into developmental psychology, the study of how humans develop through life, yields interesting insights into this psycho-philosophical problem.
Jean Piaget was a developmental psychologist who studied the development of children throughout the 20th-century. Today, his influence is still felt in psychological literature and continues to impact thought regarding childhood development. For years he observed, tested, and took notes on infants, from birth to early adulthood, using the data to devise his famous theory of cognitive development, which takes place in four stages: Sensorimotor, preoperational, concrete operational, and formal operational. The first stage, sensorimotor, takes place starting at birth and ending at the age of two. During this period, the baby’s life is geared toward adjusting to the world. Babies are “thrown” into this world, to use a Heideggerian term. They are born immediately into life amidst chaos, with all kinds of new stimuli to which to react. Confused, unable to make sense of things, exposed to strange sights and sounds, the baby cries and thrashes about, trying to find some sense of security. It is bombarded all at once by sensations and experiences. It is disoriented. This is a brave new world, and it is full of data that needs to be interpreted and sorted out in the baby’s mind. In order to navigate through the world, the newborn uses its motor skills and physical senses to experience things. The baby interacts with its environment, including people, grabbing with its hands, sucking with its mouth, hearing with its ears, and smelling with its nose. Imagine being in a cave for years, devoid of all sensory information, when, one day, you are let out and, having forgotten what it was like to experience the world, you are overcome by the magnitude of the environment, so you try to relearn as much as possible, greedily taking in everything that you can—well, being in the womb is kind of like being in a cave for the baby, meaning it is doing the same thing: It is getting a grasp of reality by engaging its senses in any way that it 
possibly can. The baby is an empiricist who delights in its senses as though life were a buffet. Oh, there is something I can touch! Ah, that smells nice, let me smell it! While it cannot yet register these sensations, the infant uses its senses to obtain a primitive understanding. They are actively mapping out the world according to their perceptions, simple though they are. According to Piaget, babies eventually learn to pair coordination, knowledge of their body and its movement, with determination. Once they are able to effectively use their body parts in a way that is conducive to their survival, they develop their sense of where these limbs are in relation to each other, called proprioception. This allows them to use determination in regard to this newly acquired coordination. Babies can now direct themselves with autonomy and do something. However, this is a simple form of determination; it is not like the baby has free will and can decide or choose to do this or that. Whereas the baby can move toward a particular object, it cannot decide mentally, “I am going to crawl over to that thing”; it just does it out of pure, unthinking volition.
At three months, a baby can sense emotions and, amazingly, recreate them. Seeing their parents sad, an infant can react to this with a fitting response, as in being sad themselves. By being able to tell what someone is feeling, the baby can imitate them, showing that the baby has at least a simple recognition of empathy. Around this time also, the baby actively listens to their social scene, picking up on spoken language. It is incredible (in both senses of the word) because it is now that the infant unobtrusively 
and quietly internalizes and processes everything it hears like a sponge, learning speech cues, such as when to talk and when to pause; the rhythms of speech, including cadence; vocabulary; and nonverbal communication, which makes up the majority of social interaction. Here is a tiny little human just crawling around the house on all fours who cries and eats and goes to the bathroom, all the while they are actually learning how to speak—who could possibly fathom what is going on in that small, undeveloped mind! A little earlier, around two months usually, the baby already shows signs of early speech when it babbles. Nonsense sounds are uttered by the baby, who is trying to imitate speech, but who is not complex enough to reproduce it entirely. Four to five months into development, the baby can understand itself as a self-to-Others, or a self-as-viewed-by-Others. I have my own image of myself, but I understand that I am perceived by other people, who form their own images of me. One study shows that, from four to nine months, the infant has changing patterns of involvement in play. In the earliest stage, the baby will, if it is approached by the parent, play peekaboo. Because they have not yet learned that things exist independent of them in time, babies think that the parent disappears when they are covered, and is surprised to find they are still there. A few months later, nine months, the baby is able to take on the role of the initiator who wants to play peekaboo, instead of the responder who will play peekaboo if asked. This proves that babies learn to combine determination with intention (Bruner, 1983).
Just three months later, when the infant is officially one year old, it achieves a self-image. Looking in the a mirror, it can recognize itself and form an early identity. Like chimps, babies can now respond to themselves as an actual self in the mirror, noticing, for example, a mark on their forehead, and realizing that it is not on the mirror, but on themselves. During 14-18 months, an infant is able to differentiate an Other’s intentions from their own (Repacholi & Gopnik, 1997). Children like to think in terms of their own desires. If a kid wants a cookie, they act on their desire. Thus, when they are 14-18 months old, they can distinguish Others’ desires as different from their 
own. Within this period, the baby can also know that it is being imitated by someone else. If a parent mimics something the infant is doing, the infant knows their own behavior is being shown to them. Finally, the 18-month marker designates when the baby begins to start its sentences with the first-person “I.” With a sense of self, the infant is able to roleplay, in which it takes on new identities, or roles, and is able to play “as them.” Second-order emotions, also known as self-conscious emotions, like shame and embarrassment, arise in the child at this time, too. Children possess some semblance of self-consciousness.
After the sensorimotor stage is what Piaget called the preoperational stage, which takes place between the ages of two and seven. It is at this stage that the infant constructs their own world. Through the process of assimilation, the toddler creates mental schemas, mini blueprints conceived in their minds, frameworks by which reality is processed then 
made sense off, allowing them to structure reality in a way that is useful to them. When a new experience is undergone, it is made to fit the pre-existing schema. Because these schemas are very simple and basic, they are obviously inaccurate, although that is not point of them; they are not supposed to be innate categories of the mind, as Kant would have thought of them, but early hypotheses made from the little experienced gathered by a child. One time, my cousins came over to play video games; we were playing a level in Lego Indiana Jones where we had to drive around on a motorcycle chasing cars. My cousin’s little brother pointed excitedly at the cars zooming down the streets, exclaiming, “Doo-doo!” I hopped on a motorcycle and chased after them, only for him to look at the motorcycle and, again, shout, “Doo-doo!” My cousin and I tried to tell him that a car and a motorcycle were two separate things. In his mind, he saw a moving vehicle with wheels, so he created a mental schema. Anything that fit under that description—a moving vehicle with wheels—would be considered by him to be a “Doo-doo”—in this case, both the car and the motorcycle, despite their being different things. This illustrates that schemas are not always accurate; they are for classifying and categorizing things. Of course, this leads to a new process observed by Piaget: Accommodation. We come to an age where we discover that our schemas are inadequate because they do not fully represent reality. As such, we have a kind of “schematic crisis,” as we are met with an anomaly, something which sticks out, something which does not fit with our prevailing theory. Hence, we must remodel our thinking. Consequently, we are forced to find a way to reconcile the already-existing category with this new piece of data, either by broadening the schema, or by creating a new one altogether. Babies thus learn to make more accurate classifications as they learn new things and create new schemas with which to interpret 
reality. Once these schemas are built up, the infant is able to engage in organization, through which they order their schemas. Some are judged to be more inclusive or exclusive than others, and so are co-ordinated based thereon. In the case of my cousin’s little brother, he would have to organize his schemas like this: Broadly, there are vehicles, under which we might find cars and motorcycles as types, which can themselves be expanded upon, for each comes in different kinds. This way, reality is structured in levels, or hierarchies, not necessarily in importance, but in generality and specificity. Organization is a synthesis of assimilation and accommodation. All this schematizing segues into the next point, namely that in making sense of the world, we give sense to it.
The preoperational period is characterized by symbolic representation in toddlers. In philosophy, the study of meaning and symbolism is called semiotics, and it is closely related to what babies do, interestingly. Life is separated into two concepts: Signs and symbols. Signs are fixed things—concrete objects. Symbols are relative meanings—abstract values—usually assigned to signs. While every car I see is always a car, its meaning is not always the same and is liable to change. For some, it can represent, can be symbolic of, freedom, if you are a teen just getting your license; transportation, if it is how you get around; dread, if you hate road trips or have to wait hours during commute. The point is, everyone sees the same sign, but for everyone the symbol has different meanings. Preoperational toddlers are able, then, to understand objects not just in their literal, concrete sense, but as standing for something, as abstract and meaningful. Babies are not passive, as I have said, but on the contrary, very much, if not entirely, active. By interacting with the world around them, they experiment, learn, and conceptualize. Around three years, the baby is fully capable of speaking, feeling, having motives, and knowing the relation of cause-and-effect.
One of the consequences of Descartes’ Cogito is its resulting solipsism: The thinker, the Cogito, is only able to prove his own existence, whereas Others’ existences are uncertain. Is this a requisite for existence? Is self-certainty a necessity? If so, the case is a difficult one for babies. Controversially, Piaget proposed that babies are egocentric; his theory is widely contested today in psychological circles. The meaning of egocentrism can be guessed by looking carefully at the word’s roots: It means self-centered; however, it is not self-centeredness in the sense of being prideful, selfish, and concerned with oneself, no—it is more closely related to anthropocentric, in the sense that the self is the central point from which all others points are judged or perceived. For this reason, Piaget suggested that infants can only see things through their own perspectives, not through Others’. You may be wondering why I sometimes have been capitalizing “Other.” Philosophically, the problem of egocentrism is closely related to solipsism, resulting in what is called “the problem of Other Minds,” which is the attempt to prove the existence of selves outside of our own, of whose existence we are uncertain, so they are called “Others,” giving them a kind of external, foreign connotation. I digress. Babies, so thought Piaget, are unable to take Others’ perspectives, so the must rely on their own perspectives. To do this, they reason from self to Other. Infants’ egocentric tendencies, when combined with their inability to acknowledge objects as existing permanently outside of them, lead to a subject-object dualism, a subjective idealism, in which the self is distinguished and utterly separated 
from the physical world. It becomes “my” viewpoint, or “your” viewpoint, subjective, relative. As long as I look at an object, a toddler thinks, it exists. And yet, the toddler also has a social self, which it develops through its interactions with other children. Many psychologists have claimed that, by playing, children are able to acknowledge the existence of not just Others, but Others’ emotions. It is evident in roleplaying, where the children pretend they are someone they are not, and act accordingly, placing themselves within a new self, which they adopt as their own, and interact with the other children, whom they see as someone else, whom they acknowledge and actively engage with, responding to how they are treated, and sensing emotions.
A dominant, popular theory that attempts to refute Piaget’s egocentrism is “Theory of Mind” ([ToM] Wellman, 1990). Wellman found that babies develop an awareness of Others at the age of three, when they operate on belief-desire reasoning. Motivation for kids consists of a belief, what they know, and a desire, what they want. A child might be motivated to have a cookie because they know where the cookie jar is, and they are hungry for one. Using this kind of reasoning, the kid attributes their own intentions to another. Looking at his playmate, the toddler assumes, “Well, I want a cookie, and I know where they are, so this kid, like me, because he has the same beliefs and desires as I, must want a cookie, too.” Is it faulty and inaccurate? Wildly. Does it make sense, realistically? Yes. The Theory of Mind is a primitive form of empathy, a kind of empathetic stepping stone. It is simple and selfish, because it assumes that 
children have the same beliefs and desires. One often sees this in children trying to console one another: An infant sees another crying, and, because he takes comfort in eating ice cream, believes the other will take comfort in it, too. Critics like Vasudevi Reddy criticize Theory of Mind because it is too detached from actual interaction and ends up actually attributing one’s own self-certitude to another, resulting in what she calls a “Neo-Cartesianism” of sorts. It promotes solipsistic thinking by denying the existence of an independent thinker with emotions, instead attributing to them own’s own ideas, thereby increasing a toddler’s dualistic thinking.
According to Reddy, a baby’s communication with Others’ already presupposed intersubjectivity, or being involved with people on a personal level. Babies are self-aware to an extent at birth because, the argument goes, the baby is able to distinguish itself from the world around it. To act, is to know both the self and the object. It is similar to Fichte’s philosophy in that the Ego becomes aware of itself by recognizing everything that is not the Ego, creating the Non-ego; in other words, it is through the Non-ego—the world—that the Ego knows itself. The world, or Non-ego, is created purely with the intent of being a moral playground for the Ego. Following from this is the idea that the baby, coming into contact with the world, immediately knows it as not-itself, and so uses it as its playground, activating all its senses to learn about reality. If we could not tell the environment apart from ourselves, and we thought ourselves a part of it, how could we act independently of it, with our senses? This is an argument against Freud and Piaget, who both said newborns cannot tell themselves from the world. As a solution to egocentrism, psychologists found that parents play an important role early on. Parents should teach their children early on to differentiate self from Other. Too much similarity between the baby and parent means more egocentrism in life, which is harder to unlearn. Reddy’s 
solution is to avoid Cartesianism and Theory of Mind and instead pursue a second-person perspective, one between I-and-Thou, You-and-I. This way, there is direct access to another’s intentions. Babies, through play, function on this second-person level by directly interacting with their peers. For Piaget, babies achieve consciousness when symbolism and schematism come together as one to create meaningful representations. An understanding of how things fit together and how they function is what Piaget considers consciousness. On the other hand, metacognition, the ability to think about thinking, does not arise until the age of 11, Piaget’s formal operational stage.
The following are milestones in the evolution of a baby’s cognitive abilities, summarized in eight chronological key events:
- Coordination
- Self vs. non-self
- Know special/loved people
- Know + respond to name
- Self-image
- Pointing to objects (symbol)
- Use “I” in sentences
- Know Other Minds
So, to answer my friend: The question of whether or not babies exist is actually not so straightforward as one might think. It could be argued that babies exist when they are one, when they establish their self-image for the first time, and thus are, in one way or another, conscious of themselves. Or it may be that babies exist once they turn 18 months, and they can use “I,” roleplay, and experience reflexive emotions. Here, babies are aware of themselves as actors, are willing to play with others and take new perspectives, and are able to perceive how they are themselves perceived by others. Yet then again, it is possible that it is only when metacognition is possible, when we are able to doubt that we are doubting, when we are able to posit a hypothetical Evil Demon trying to deceive us all, that we exist—in which case… babies do not exist at all! Do only children and preadolescents and onwards exist? Maybe when we are born, we do not exist, we are in a state of utter nonexistence and non-being, and it is only when we reach 11 that—POOF!—we magically pop into existence.
[1] This is obviously a satirical question. Babies do exist. It is more of a thought-experiment, or armchair philosopher problem. I find the comment to be so outrageous that it is funny, and I thought it made for a perfect reason to research if babies are conscious.
For further reading: How Infants Know Minds by Vasudevi Reddy (2008)
Developmental Psychology 8th ed. by David R. Shaffer (2010)
The Secret Language of the Mind by David Cohen (1996)
The Science of the Mind by Owen J. Flanagan, Jr. (1984)
Neologikon 