I've been dipping in and out of a bunch of books recently! Last night took me into Koestler's The Ghost in the Machine from 1967. I've read bits of a few of Koestler's books; I don't know much about his intentions or broader perception, but I tend to like his casual tone while challenging widely-held conventions.
Here are a few bits I highlighted while reading, as he goes through how strange it is that the dominant form of psychological research in the early 20th century was dedicated to ignoring consciousness. It's still relevant-feeling now because of the widespread application of Pavlovian/Behaviorist ideas and mechanisms throughout our world, particularly in software/game development and their deliberate lean into psychological manipulation.
By far the most powerful school in academic psychology, which at the same time determined the climate in all other sciences of life, was, and still is, a pseudoscience called Behaviourism. Its doctrines have invaded psychology like a virus which first causes convulsions, then slowly paralyses the victim.
On the strength of this doctrine, the Behaviourists proceeded to purge psychology of all 'intangibles and unapproachables'. The terms 'consciousness', 'mind', 'imagination' and 'purpose', together with a score of others, were declared to be unscientific, treated as dirty words, and banned from the vocabulary. In Watson's own words, the Behaviourist must exclude 'from his scientific vocabulary all subjective terms such as sensation, perception, image, desire, purpose, and even thinking and emotion as they were subjectively defined'.
Psychology used to be defined in dictionaries as the science of the mind; Behaviourism did away with the concept of mind and put in its place the conditioned-reflex chain.
In his standard work Science and Human Behaviour the hopeful student of psychology is firmly told from the very outset that 'mind' and 'ideas' are non-existent entities, 'invented for the sole purpose of providing spurious explanations. . . . Since mental or psychic events are asserted to lack the dimensions of physical science, we have an additional reason for rejecting them'.  By the same logic, the physicist may, of course, reject the existence of radio waves, becanse they are propagated through a so-called 'field' which lacks the properties of ordinary physical media. In fact, few of the theories and concepts of modern physics would survive an ideological purge on Behaviourist principles — for the simple reason that the scientific outlook of Behaviourism is modelled on the mechanistic physics of the nineteenth century.
The attempt to reduce the complex activities of humanity to the hypothetical 'atoms of behaviour' found in lower mammals produced next to nothing that is relevant — just as the chemical analysis of bricks and mortar will tell you next to nothing about the architecture of a building. Yet throughout the dark ages of psychology most of the work done in the laboratories consisted of analysing bricks and mortar in the hope that by patient effort somehow one day it would tell you what a cathedral looked like.
The unique attributes of humanity, verbal communication and written records, science, art, and so forth, are considered to differ only in degree, not in kind, from the learning achievements of the lower animals — once more epitomised, for Hull as for Skinner, in the bar-pressing activities of the rat. Pavlov counted the number of drops which his dogs salivated through their artificial fistulae, and distilled them into a philosophy of man; Professors Skinner, Hull and their followers took an equally heroic short cut from the rat in the box to the human condition.
Skinner did not intend to write a parody.* He means it seriously.
Both are engaged in question-begging on a heroic scale, apparently driven by an almost fanatical urge to deny, at all costs, the existence of properties which account for the humanity of the human and the rattiness of the rat.
[...] the crude slot-machine model, in its modernised, more sophisticated versions, has had a profounder influence on them — and on our whole culture — than they realise. It has permeated our attitudes to philosophy, social science, education, psychiatry. Even orthodoxy recognises today the limitations and shortcomings of Pavlov's experiments; but in the imagination of the masses, the dog on the laboratory table, predictably salivating at the sound of a gong, has become a paradigm of existence, a kind of anti-Promethean myth; and the word 'conditioning', with its rigid deterministic connotations, has become a key-formula for explaining why we are what we are, and for explaining away moral responsibility.
At first its intention was merely to exclude consciousness, images and other non-public phenomena as objects of study from the field of psychology; but later on this came to imply that the excluded phenomena did not exist.
This is one of the most frustrating things to me about the reductive scientific worldview, which persists here almost 60 years later. Thinking exists, it happens, you're doing it right now. What it is, exactly, is up for discussion, but it's trash semi-intellectualizing to assert that the sum of human (and other animal!) consciousness can be reduced to on-off electricity in a salt barrier, as one smarmier-than-thou scientist asserted to me a few years ago. Those things might be observable, but they don't add up to anything approaching the whole!
Werner Heisenberg, one of the greatest living physical scientists, has laconically declared: 'Nature is unpredictable'; it seems rather absurd to deny the living organism even that degree of unpredictability which quantum physics accords to inanimate nature.
It is impossible to arrive at a diagnosis of humanity's predicament — and by implication at a therapy — by starting from a psychology which denies the existence of mind, and lives on specious analogies derived from the bar-pressing activities of rats. The record of fifty years of ratomorphic psychology is comparable in its sterile pedantry to that of scholasticism in its period of decline, when it had fallen to counting angels on pin-heads — although this sounds a more attractive pastime than counting the number of bar-pressings in the box.
And finally, a side note as he acknowledges he's made some of these points in earlier books:
It is embarrassing to have to repeat, over and again, that two half-truths do not make a truth, and two half-cultures do not make a culture.