Determinism is essentially the philosophical and physical conviction that the evolution of the world and the future is determined, fixed, and predestined. In this case, there is no free will or actual chance, only time running its well-defined course.
Physical determinism is a monistic belief that only physical matter is actually the only independant substance and consciousness occurs as an epiphenomenon of neurological and biological and thus physical processes, which operates strictly in a determinist fashion. This also ties into the conclusion that the world is not created in the mind. There is a mind-independant world, it is even the mind that is world-dependant.
The determinist approach to physics, well-documented and hegemonic in the field until the 1920s, is contested to a degree by the invention or discovery of quantum physics at that time and until now. The reasoning for physically coherent scientific determinism is that quantum movement happens at such a minute scale compared to the interactions at a more macroscopic scale, that quantum interactions and phenomena are not influential on the course of the universe. This allows the concept of certainty and absolute causality to maintain itself in a determinist spirit.
So, is determinism interesting? On one hand, instinctively, the idea that the mind is predetermined in its course and its choices, that we have no actual free will, is frightening. It feels like the depth of our feeling, and our effort, are not justified, or are dismissed by this assertion. But it is not so: we still experience our life and consciousness fully. We still feel things, and we do the work, and we choose things. We were just destined to choose them. This is perhaps (I cannot speak to this myself) easier for believers in fate/God’s will: we are still extant as persons but within a framework where what happens happens.
And there is not either any coercion, the next steps are not arbitrary. Everything from an atomic level outwards simply follows simple laws. And the future does not have to be less exciting for this. In a way, the following steps are not written, we could not know them now; they are following steps in a process with laws, with some rules that say where which particle goes towards.
The argument that determinism believes the mind is dependant on the world can be obfuscating, since we can be led to believe physical determinism is materialist. However, this is also untrue. Materialism as we use the word today is the belief that material things are more substantial than mental and immaterial things; I am not using here the term in the Marxian dialectical sense. But on the contrary, as I stress, the statement that thoughts are a product of «material» (physical) reality is also an affirmation of the reality of thoughts. They are still as valuable as material reality and as we are conscious within them perhaps they are more so still. (If we actually otherwise use the term Materialism in its Marxian sense, we also see the application of physical determinism in the concept of dialectal materialism and its assertion that social conditions predispose different classes to struggle, in a dialectical system. On a societal scale, that involves human decision-making, we can see how people are driven to their actions and through their lives, with variations, by their material conditions. This pattern shows up in wealth distribution, generational wealth patterns, crime and deviance statistics, political dissatisfaction, etc.) The question of what the patterns and dynamics that clearly show up in society are is separate but related to the more direct lower-scale biological and molecular determinism, and it is still as valid a question, if not more so, justified by the fact there are such laws of nature and physics and similarly it’s likely there would be societal laws of physics; the field of sociology surely will one day be related back to the field of biology, this to chemistry, and the sum to the basic quantum and subatomic physics, deterministic factors at every scale.
Try as well to consider that any higher power, anyone controlling fate, anything fundamentally illogical, is immediately discarded by this. There can be no higher power if everything is determined. And if there is, since we are picturing it deterministically, they still are determined as well, which implies they have no free will of their own, which makes them just as screwed as the rest of us.
And if you are still bitter about your consciousness being «fake» and driven by crude material, determined, not really free, consider how much these determined minds can do, you see a pattern in the colour of light hitting your retina, and you, YOU, the person, recognise blood, & flinch. You can think about such things as your own emotions, and the consciousness’s own nature (I believe a common puzzle for programming language makers is to write a program that prints its own source code. We have achieved this which perhaps is celebratable.)
You can feel these ways, imagine many things, think, ponder, hear music and dream. You think of someone and you can recall the feeling of being with them. And our mark in the world, with philosophy and culture and language and history, with so many stories and thoughts had by several tens of billions of humans through history.
Physical determinism does not end all this or reduce its value. It brings us renewed admiration for the perfect clockwork fate of the world, and for the marvels that our consciousness provides for itself to enjoy… Thoughts, dreams, feelings, they feel so much more real, actually, when we are aware that they ARE real. As I have said: they have a mark and a presence in the world, an identity, they are Existing. Determinism helps us stay anchored in this feeling that everything, anytime, is determined. Whatever happens will happen. We can feel apathetic, but we don’t have to, and often we don’t, because we know this, perhaps, in ourselves. We can be angry at the world for this, for being this way, pointless and material. But we are part of it, and sometimes we should let ourselves watch our selves dance.