1) In this universe, it appear that there is a property -- lets call it mass -- that determines how things pull towards each other. But our universe is just a sample of size 1; so that might be confirmation bias or suppressed evidence.
In order to learn more about related phenomena, one needs multiple data points with varying initial conditions. In order to understand more details about a specific case, no further data points are needed or desirable. Graham's essay is about his interaction with, and opinions about philosophy; he doesn't need any other data points in order to tell you his opinion, nor do you need any other data points to talk about history.
2) Actually, one would nominally point to the start of both fields in Thales, who was seen by Aristotle to be the progenitor of Greek philosophy, and supposedly was the first person to note that the angle inscribed in a semicircle is always right. Note that, even before that, there definitely existed at least non-trivial arithmetical problems (such as finding the volumes of various solids), that were known literally a millennium prior (to learn more, consider the wiki pages for Thales, the history of mathematics, and Egyptian mathematics).
Of course, this is brushing under the carpet the fact that in Ancient Greece, the distinction between a "philosopher", a "mathematician", and a "scientist" did not yet exist (exception: physician was an independent job title); the Greeks could not have seen themselves as anything less than all three. Graham's claims have much more to do with the fact that philosophy, as an independent field, continued to exist long after this distinction became clear.
3) Your claim here is not entirely clear. Are you really trying to validate the failed methods of philosophy by saying that it's important that we try them now so that we don't make the mistake of trying them later?
4) Three of your examples date from 1750 to 1850, and are examples of how enlightenment thinking bridged the gap from philosophy into what could actually begin to be called science--these people were called philosophers because there was no other word yet extant to describe what they did, but we now recognize their results as belonging to other fields. The fact that they called themselves philosophers is irrelevant; their results did not in any way require the existence of the rest of the field of philosophy.
The important contributions of Russel and Whitehead to mathematics might have been inspired by their personal philosophies, but having such a philosophy does not require the existence, import, or study of the many misshapen works of the field.
Finally, Popper is an example of exactly what philosophy can do to actually be useful--answer a question about how to approach the gathering and use of knowledge.
In summary, what he wants philosophy to do is indeed science...so why are there still philosophers doing anything else?
1. This is an excellent point you make. There is, a priori, very little reason (as far as I know) to assume that an alternative universe would have the same physical properties as ours. If there is evidence in that direction I doubt it's merely "because our universe has this property."
But I agree with you in principle that this is a weak point. The essay's point was to respond to pg's attacks. jsomers never assumed that pg's single paper had somehow thrown philosophy into chaos and shambles.
2.I agree with you here that there is little distinction between these fields in Greece. But that's an interesting fact isn't it--it's essentially conceding that at least initially philosophy played an important role in the development of math and science (one certainly can't assume that the development of philosophy and math were going in two different tracts in the same man's head).
3.He's not saying that philosophy failed. He's arguing that pg is finding fault ex post facto. It's easy to fault Kant after you've read a response but perhaps without Kant the response (and the progress that supposedly came with it) never would have occurred.
For an analogous situation--Galois developed his theory which allowed for a proof that no polynomial of order 5 or greater was guaranteed a solution by radicals. Does this mean that Ruffini was a putz because he could only do most of the proof for order 5 polynomials? After all--he was clearly taking the wrong approach.
Or, do we think Pascal is an idiot because Newton developed the calculus that solved the problems he could not? No.
The point is that everything builds on everything. I think somers' Kant tree is a great example of this.
4. This is backwards. The point is that philosophical reasoning often led to the creation of entirely new fields of thought. Economics, politics, law and linguistics are great examples of this.
Would we have modern legal thought without the works of philosophers like Locke, Berkeley, Hume and Hobbes?
Would we have modern economics without the work of Smith, Pareto and Mill?
Would we have modern sociology without Marx and Gramsci?
That they called themselves "philosophers" is not irrelevant whatsoever. It demonstrates that philosophy often lays the groundwork for entirely new fields.
It's strange you say that their results did not require the existence of the rest of the field of philosophy. I suspect they would disagree as they seemed to rely on other philosophers in their own work.
Philosophy, at one point, was the catch-all phrase for any type of thought. Mathematics was philosophy. Science was philosophy. Law was philosophy. Economics was philosophy. Every form of thought (more or less) was philosophy. Over the course of history, these fields have spun off from philosophy, and achieved various degrees of relevance; their earliest works were done by "philosophers" because these fields did not yet exist, but in modern times they are studied independently. The question then becomes, in modern times, what is a person studying when they study philosophy? They are not studying any of the fields that spun off of philosophy, or else they would no longer be classified as philosophers. So, the question becomes (answering your point 5) what problems that other fields care about are still answered by philosophers? The critique in the OP correctly identifies that some philosophers still concern themselves with problems related to cognitive science, which still answer questions from psychology. But once cognitive science becomes its own independent field, there may be nothing left within the realm of philosophy.
We might not have had modern political science without Locke, Berkeley, Hume, and Hobbes. But we would have had Hobbes even if he had not been classified as a philosopher, and thus we would have had the rest of them.
We might not have had modern economics without Smith, Pareto, and Mill. But we would have had Smith even if he had not been classified as a philosopher, and thus we would have had the rest.
We might not have had modern sociology without Marx and Gramsci. But we would have had Comte even if he hadn't been classified as a philosopher, and thus we would have had the rest.
I mention these three individuals' work because they (1) fundamentally began what came to eventually be their fields, and (2) did not really build these fields incrementally out of the rest of the philosophical body of knowledge at the time. This demonstrates that it isn't some kind of unifying thread within the study of philosophy that causes these fields to spin off from them; philosophy was just what you called it when you were studying problems that weren't in their own field yet. This no longer occurs in modern times, so we don't see philosophy spinning off new fields in the way that it used to; computer science (as a whole) sees its roots in modern mathematics, not philosophy. Psychoanalysis, as a modern field (unlike psychology as a whole, which also often refers to much older studies), clearly descends from biology. Electrical engineering. Nuclear physics even has it in the title.
The study of the works of "philosophers" can still be relevant within other fields, but to study philosophy is to spend one's time looking at what's left. It is this study, in modern times, that pg and I are attacking as vague, useless, and prone to wars of semantics.
In order to learn more about related phenomena, one needs multiple data points with varying initial conditions. In order to understand more details about a specific case, no further data points are needed or desirable. Graham's essay is about his interaction with, and opinions about philosophy; he doesn't need any other data points in order to tell you his opinion, nor do you need any other data points to talk about history.
2) Actually, one would nominally point to the start of both fields in Thales, who was seen by Aristotle to be the progenitor of Greek philosophy, and supposedly was the first person to note that the angle inscribed in a semicircle is always right. Note that, even before that, there definitely existed at least non-trivial arithmetical problems (such as finding the volumes of various solids), that were known literally a millennium prior (to learn more, consider the wiki pages for Thales, the history of mathematics, and Egyptian mathematics).
Of course, this is brushing under the carpet the fact that in Ancient Greece, the distinction between a "philosopher", a "mathematician", and a "scientist" did not yet exist (exception: physician was an independent job title); the Greeks could not have seen themselves as anything less than all three. Graham's claims have much more to do with the fact that philosophy, as an independent field, continued to exist long after this distinction became clear.
3) Your claim here is not entirely clear. Are you really trying to validate the failed methods of philosophy by saying that it's important that we try them now so that we don't make the mistake of trying them later?
4) Three of your examples date from 1750 to 1850, and are examples of how enlightenment thinking bridged the gap from philosophy into what could actually begin to be called science--these people were called philosophers because there was no other word yet extant to describe what they did, but we now recognize their results as belonging to other fields. The fact that they called themselves philosophers is irrelevant; their results did not in any way require the existence of the rest of the field of philosophy.
The important contributions of Russel and Whitehead to mathematics might have been inspired by their personal philosophies, but having such a philosophy does not require the existence, import, or study of the many misshapen works of the field.
Finally, Popper is an example of exactly what philosophy can do to actually be useful--answer a question about how to approach the gathering and use of knowledge.
In summary, what he wants philosophy to do is indeed science...so why are there still philosophers doing anything else?