Most people think of Sigmund Freud as a psychologist or a psychiatrist. But he was neither. He was trained as a neuroscientist and went on to create a new discipline that he called ‘psychoanalysis’. But Freud should also be thought of as a philosopher – and a deeply insightful and prescient one at that. As the philosopher of science Clark Glymour observed in 1991:
Freud’s writings contain a philosophy of mind, and indeed a philosophy of mind that addresses many of the issues about the mental that nowadays concern philosophers and ought to concern psychologists. Freud’s thinking about the issues in the philosophy of mind is better than much of what goes on in contemporary philosophy, and it is sometimes as good as the best …
In fact, it’s impossible to really understand Freudian theory without coming to grips with its philosophical undercurrents. This might sound strange, given the many derogatory remarks about philosophy that are scattered through Freud’s writings and correspondence. But these remarks are easy to misinterpret. Freud’s verbal barbs were not directed at philosophy per se. They were directed at the kind of philosophy that was dominant during his lifetime – philosophy of the speculative, armchair variety that remains aloof from scientific investigations of the material world, often described as ‘metaphysics’, a subject that he characterised as ‘a nuisance, an abuse of thinking’, adding: ‘I know well to what extent this way of thinking estranges me from German cultural life.’
To come to grips with the philosophical thrust of Freud’s thinking, it is crucial to place it in its historical context. Born in 1856 in a village in what is now the Czech Republic, Freud enrolled in the University of Vienna just at the time when the sciences of the mind were gaining momentum. Although he initially planned to study law with the intention of pursuing a career in politics, and also toyed with the idea of doing a joint PhD in zoology and philosophy, he eventually found his way to neurology. In entering this field at just that moment, the young Freud launched himself into an incredibly exhilarating and dynamic intellectual milieu.
For neuroscientific researchers, the daunting scientific challenge of figuring out how the brain works (without the benefit of the sophisticated technologies available today) was compounded by the equally formidable philosophical challenge of explaining the relationship between the electrochemical impulses coursing through a massively complex network of neurons and the experiential fabric of our subjective mental lives – our thoughts, values, perceptions, and choices.
At around the same time that neuroscience was finding its feet, psychology was emerging as a new scientific discipline (prior to about 1879, psychology was considered to be part of philosophy). The early psychologists were also confronted with a deep philosophical problem, albeit a methodological one. How is it possible to investigate the human mind scientifically? Mental phenomena are by their very nature subjective, but science demands an objective stance towards what is being investigated. In light of this seeming contradiction, there was a real question about whether a science of the mind was even possible – which led some to exclude the psyche from psychology, and to redefine it as the scientific study of behaviour.
Unlike most scientists today, the neuroscientists and psychologists of that era understood that science is inevitably rife with philosophical assumptions. For the most part, they worked within a paradigm that they had inherited from the 17th-century polymath René Descartes. Two components of the Cartesian intellectual tradition were especially relevant to their work. One concerned the ‘mind-body problem’ – the problem of understanding the precise relation that holds between our mental states and our bodily states. The other concerned what might be called ‘the mind-mind problem’ – the problem of understanding how our minds are related to themselves. The first of these was primarily of interest to neuroscientists, while the second was mainly of interest to psychologists.
With regard to the first problem, 19th-century neuroscientists mostly took the view that minds and bodies are radically different kinds of things. Bodies are material things – flesh-and-blood machines that can be studied from a third-person perspective. But minds are immaterial things that can be accessed only from the ‘inside’, a view that was later ridiculed by the British philosopher Gilbert Ryle as the theory of ‘the ghost in the machine’. With regard to the second problem, psychologists had the view that minds are transparent to themselves – in other words, that the mind is entirely conscious. Each of us has direct access only to our own mental states, and we cannot be mistaken about those states. This implied that psychological research should proceed by means of introspection, which is why the first psychologists came to be known as ‘introspectionists’.
During the course of the 19th century, the Cartesian concept of mind-body dualism came under increasing pressure. Early on, the law of the conservation of energy – the principle that the quantity of energy in the physical universe remains constant – clashed with the notion that bodily movement is explained by a non-physical mind injecting energy into the physical world.
The study of the aphasias, disorders of speech caused by lesions to the brain, showed that the mental faculty of language was intimately bound up with particular regions of the ball of nerve tissue between our ears. And Charles Darwin’s theory of evolution supported the idea that every aspect of human beings – including their mental capacities – evolved in response to physical selection pressures.
At roughly the same time, research into hypnosis was challenging the idea that the mind is transparent to itself. Hypnotic experiments demonstrated that a person could be placed in a trance and be given the instruction to perform some action upon awakening in response to a certain signal.
For instance, the hypnotist might tell his subject that upon hearing the word ‘bluebird’ he would drop to the floor and crawl around on hands and knees. And sure enough, upon hearing the trigger, he would do just that. When asked why he was crawling on the floor, the subject would confabulate – saying, for instance, that he had lost a key and was trying to find it. Such experiments seemed to demonstrate not only that there can be unconscious ideas – thus refuting the belief that the mind is entirely conscious – but also that such ideas can have the power to shape behaviour.
These centres of consciousness were considered akin to separate persons inhabiting a single human brain
Scientists of the mind responded to this sort of challenge with two explanatory strategies, both based on the assumption that nothing that is mental can be unconscious, and nothing that is unconscious can be mental. Some granted that ostensibly unconscious mental states were indeed mental but insisted that they were not really unconscious. According to this view, a person’s consciousness can be split apart, resulting in a ‘main’ consciousness and one or more ‘sub’-consciousnesses, an approach that’s sometimes called dissociationism. These hypothetical centres of consciousness were considered to be something akin to separate and distinct persons inhabiting a single human brain, each of which has direct access only to its own mental states, but without access to the mental states of the others.