After reading the first chapter:
First off, it's an well written book. Chapter 1 titled "The Reach of Explanations" is excellent at explaining science as essentially the quest for better explanations, and the Enlightenment as the point in time where this kicked off in earnest. It makes a great case for what constitutes a good vs. a bad explanation, etc, etc. In the spirit of the chapter's purpose, I have nothing to complain about.
However, the book was recommended to me explicitly as the best refutation of the computational theory of mind, and therefore I of course tried to find something on that topic in every bit I read.
With that in mind, I can't help but notice that the first chapter already is full of biases and inconsistencies that curl my toenails.
The author doesn't specifically mention anything on the computational theory of mind, but veers off into epistemology. That he condemns empiricism and inductivisim to the scrap heap of history is fair enough. He explains well enough that they were steps up from previous explanations on reasoning which required a priori knowledge of the working of the world, he then goes on to explain reasoning in kind of, but not quite, the abductive model. Except he phrases the entire thing without mentioning the terminology, and in a way that would require a priori knowledge to function, which contradicts his earlier criticism.
The simpler explanation would be that abductive reasoning is inductive reasoning based on incompletely understood empirically collected data. To top off my annoyance, that is not the current state of the art in scientific endeavours (caveat: based on the papers I read, which is admittedly not an input set representative of the whole of science). That appears to be Bayesian statistics, which could - for the sake of brevity - be described as a cyclic refinement of abductive reasoning trending towards inductive reasoning, based on ever improving empirically collected data.
Or, to put it in a nutshell, all of the "bad reasoning" approaches Deutsch decries connected in a way that would allow abolishing the "good reasoning" approach he seems to like.
Interestingly, that doesn't change that the chapter is actually good. It just seems that someone bowed out of the entire train of thought just before the end because it got complicated. I somewhat doubt that's Deutsch himself, so it must have been the intended readership. Deutsch or his editor(s) seem to think scientific reasoning is too complex to explain fully, so they hacked away at the explanations to make them much simpler, leaving a solid enough story at a shallow read, but a jumbled mess at a deeper read.
(See what I did above, by the way? I gave the shallow read/easy explanation after the deep read/complex explanation as a TL;DR summary. I'm not saying that's the only way to solve this dilemma, nor that it's the best, but it's one way of keeping more readers on board.)
So with that written, I have the expectation set that the remainder of the book will be good with fairly painful moments. We'll see how it goes. When I'm done reading, I hope I'll update this review.
After Chapter 3
Chapter 2 was fine. I have nothing to complain about (yes, I'm complaining, I realize that). So I will turn to Chapter 3.
The topic of Chapter 3 is how human activity is a "spark" for turning an otherwise knowledge-free universe into one generating knowledge. It reads as if it is intended to encourage scientific endeavour, and I suppose it does. I approve of this goal, even.
And yet, individual passages drive me nuts because of their logical fallacies. It seems as if Deutsch arrives at the best possible conclusion precisely because he misunderstands some things and misconstrues others. If all I cared about were effects, I wouldn't mind, but I also care about causes.
So, let's go through my main annoyances.
Deutsch uses the Principle of Mediocrity ("there's nothing special about humans on the cosmic scale") and the Spaceship Earth Metaphor ("earth is a uniquely suitable biosphere travelling through hostile space") to explain that they are both not in fact enlightened points of view, but rather backwards. I understand the second somewhat, and for space reasons I'm going to skip it.
But his explanation for challenging the Principle of Mediocrity is so contrived, it is painful. The Principle states more fully that because there are countless planets like ours orbiting suns like ours, which therefore have the same conditions as ours, it's likely that there'll be creatures like ourselves, which makes us anything but not special. His counter argument is that on the contrary, we are special, because for all the countless places in the universe with exactly earth-like conditions, there are orders of magnitude more places which have very different conditions.
He's right, of course, that precisely because earth-like conditions are rare, they are special. But he's wrong in assuming that must mean that the Principle of Mediocrity is wrong. Because what it says encodes a different point of view than mere statistics; it states that small enough differences are negligible.
Because, let's face it, there are no conditions exactly earth-like in the universe unless there's some kind of mirroring. Other earth-like planets orbiting earth-like suns will not have the exact same other count, or size of planetary objects in the solar system. Yet these differences do not matter, because they leave conditions sufficiently earth-like.
So if these small differences do not matter, what about almost-earth-like conditions? What about conditions where everything is earth-like, but there are two smaller moons? They will influence tides differently, and may create conditions in which earth-like life cannot arise. What about almost-almost-earth-like conditions?
If you examine the universe by similarity, you can reach to its ends (hypothetically speaking) and for every part of space find a part that's comparable enough. So the question is: what makes earth-like more special than almost-earth-like or any of the other closely related conditions? Nothing, except us. We live only in earth-like conditions.
Which means Deutsch is essentially espousing the kind of anthropomorphic point of view he accuses the Principle of Mediocrity to espouse, and... hilarity ensues! But apparently that's not something he sees, or wishes to see.
There are a number of similar anthropomorphism he commits to, and similar gaps in his argumentation. But the culmination of it is the conclusion of his chapter, stating that people matter in the cosmic scheme of things because they generate knowledge.
His chain of argumentation isn't wrong. It's just a particular point of view, that values the abstract concept of knowledge more highly than the brains in which the knowledge is encoded. What the entire chapter is stating, really, is that he wants meaning to be meaningful precisely because humans create meaning out of the information the universe contains.
The argument he provides is that humans purposely affecting their environment changes how other intelligent beings would perceive our environment. Their scientific models might predict the atmosphere to contain less pollutants, but they perceive more, so they must adjust their models to that fact - and only including human activity will provide a good model.
So that's fine, in itself. What's puzzling - other than explaining it by wishful thinking - is where he draws the difference between purposeful human activity and other natural processes.
Viewed from a distance, an inflammation is reddened and swollen flesh and skin, possibly producing pus. Viewed more closely, all of these are symptoms of underlying mechanisms, all of which purposefully fight an infection. The swelling constricts blood vessels, somewhat isolating the infected area from others. The pus are dead white blood cells bound to whatever they're fighting off.
Similarly viewed from a distance, pollutants in the atmosphere are just there. When you look more closely, you might find either a lot of volcanic activity, or human activity causing it. Of course when examining the causes it's important to make this separation, but if the effect is the same, why other than arbitrary choice is one cause more important than another? Put differently, what makes purposeful human activity more important than any other physical or chemical process in the universe?
Only the meaning we attribute to it. So people are meaningful because we want them to be meaningful, and here the cat bites its own tail. Deutsch falls for the anthropomorphism fallacy so hard, he doesn't even see it in himself, only in others.
It's sad to read.
And yet, his message that we should rejoice in how we can affect the universe, and should accumulate knowledge in order to ever improve our conditions, well... I can't argue with that. I just attribute it to fulfilling my biological imperative, i.e. chemical rewards, i.e. fun - and egotism, which is the mental construct for the same.
Anyway. After this, I expect to be back for more at a later chapter.
