# A reply to Mark Linsenmayer about philosophy

[Mark Linsenmayer](http://www.partiallyexaminedlife.com/about-the-participants/), one of the hosts of a top philosophy podcast called _[The Partially Examined Life](http://www.partiallyexaminedlife.com/)_, has written a [critique](http://www.partiallyexaminedlife.com/2013/01/03/eliezer-yudkowsky-and-luke-muehlhauser-on-modern-rationalism-conversations-from-the-pale-blue-dot/) of the view that [Eliezer](http://yudkowsky.net/) and I seem to take of philosophy. Below, I respond to a few of Mark's comments. Naturally, I speak only for myself, not for Eliezer.

> I'm generally skeptical when someone proclaims that "rationality" itself should get us to throw out 90%+ of philosophy...

[Sturgeon's Law](http://en.wikipedia.org/wiki/Sturgeon's_Law) declares that "90% of everything is crap." I think _something_ like that is true, though perhaps it's 88% crap in physics, 99% crap in philosophy, and 99.99% crap on [4chan](http://www.4chan.org/).

But let me be more precise. I _do_ claim that almost all philosophy is useless _for figuring out [what is true](/lw/eqn/the_useful_idea_of_truth/)_, for reasons explained in several of my posts:

*   [Philosophy: A Diseased Discipline](/lw/4zs/philosophy_a_diseased_discipline/)
*   [Concepts Don't Work That Way](/lw/4zs/philosophy_a_diseased_discipline/)
*   [Intuitions Aren't Shared That Way](/lw/foz/philosophy_by_humans_3_intuitions_arent_shared/)
*   [Train Philosophers with Pearl and Kahneman, Not Plato and Kant](/lw/frp/train_philosophers_with_pearl_and_kahneman_not/)

Mark replies that the kinds of unscientific philosophy I dismiss can be "useful at least in the sense of entertaining," which of course isn't something I'd deny. I'm just trying to say that Heidegger is pretty darn useless for figuring out what's true. There are thousands of readings that will more efficiently make your model of the world more accurate.

If you want to read Heidegger as poetry or entertainment, that's fine. I watch _Game of Thrones_, but not because it's a useful inquiry into truth.

Also, I'm not sure what it would mean to say we should throw out 90% of philosophy _because of rationality_, but I probably don't agree with the "because" clause, there.

> \[Luke's\] accusation is that most philosophizing is useless unless explicitly based on scientific knowledge on how the brain works, and in particular where intuitions come from... \[But\] to then throw out the mass of the philosophical tradition because it has been ignorant of \[cognitive biases\] is \[a mistake\].

I don't, in fact, think that "most philosophizing is useless unless explicitly based on scientific knowledge \[about\] how the brain works," nor do I "throw out the mass of the philosophical tradition because it has been ignorant of \[cognitive biases\]." Sometimes, people do pretty good philosophy without knowing much of modern psychology. Look at all the progress Hume and Frege made.

What I _do_ claim is that many _specific_ philosophical positions and methods are undermined by scientific knowledge about how brains and other systems work. For example, I've [argued](/lw/7tz/philosophy_by_humans_1_concepts_dont_work_that_way/) that a particular kind of philosophical analysis, which assumes concepts are defined by necessary and sufficient conditions, is undermined by psychological results showing that brains don't store concepts that way.

If some poor philosopher doesn't know this, because she thinks it's okay to spend all day using her brain to philosophize without knowing much about how brains work, she might spend several years of her career pointlessly trying to find a necessary-and-sufficient-conditions analysis of knowledge that is immune to Gettier-style counterexamples.

That's one reason to study psychology before doing much philosophy. Doing so can save you lots of time.

Another reason to study psychology is that psychology is a significant component of [rationality training](http://appliedrationality.org/) (yes, with daily study and exercise, like piano training). Rationality training is important for doing philosophy because [philosophy needs to trust your rationality even though it shouldn't](/r/lesswrong/lw/fpe/philosophy_needs_to_trust_your_rationality_even/).

> ...Looking over Eliezer's site and Less Wrong... my overall impression is again that... none of this adds up to the blanket critique/world-view that comes through very clearly

Less Wrong is a group blog, so it doesn't quite have its own philosophy or worldview.

_Eliezer_, however, most certainly does. His approach to epistemology is pretty thoroughly documented in the ongoing, book-length sequence [Highly Advanced Epistemology 101 for Beginners](http://wiki.lesswrong.com/wiki/Highly_Advanced_Epistemology_101_for_Beginners). Additional parts of his "worldview" comes to light in his many posts on [philosophy of language](/lw/od/37_ways_that_words_can_be_wrong/), [free will](http://wiki.lesswrong.com/wiki/Free_will_(solution), [metaphysics](http://wiki.lesswrong.com/wiki/Reductionism_(sequence), [metaethics](http://wiki.lesswrong.com/wiki/Metaethics_sequence), [normative ethics](/lw/n3/circular_altruism/), [axiology](/lw/xy/the_fun_theory_sequence/), and [philosophy of mind](http://wiki.lesswrong.com/wiki/Zombies_(sequence).

I've written less about my own philosophical views, but you can get some of them in two (ongoing) sequences: [Rationality and Philosophy](http://wiki.lesswrong.com/wiki/Rationality_and_Philosophy) and [No-Nonsense Metaethics](http://wiki.lesswrong.com/wiki/No-Nonsense_Metaethics).

> I think it's instructive to contrast Eliezer with David Chalmers... who is very much on top of the science in his field... and yet he is not on board with any of this "commit X% of past philosophy to the flames" nonsense, doesn't think metaphysical arguments are meaningless or that difficult philosophical problems need to be defined away in some way, and, most provocatively, sees in consciousness a challenge to a physicalist world-view... I respectfully suggest that while reading more in contemporary science is surely a good idea... the approach to philosophy that is actually schooled in philosophy a la Chalmers is more worthy of emulation than Eliezer's dismissive anti-philosophy take.

Chalmers is a smart dude, a good writer, and fun to hang with. But Mark doesn't explain here _why_ it's "nonsense" to propose that truth-seekers (_qua_ truth-seekers) should ignore 99% of all philosophy, _why_ many metaphysical arguments aren't meaningless, _why_ some philosophical problems can't simply be dissolved, nor why Chalmers' approach to philosophy is superior to Eliezer's.

And that's fine. As Mark wrote, "I intended this post to be a high-level overview of positions." I'd just like to flag that arguments weren't provided in Mark's post.

Meanwhile, I've linked above to many posts Eliezer and I have written about why most philosophy is useless for truth-seeking, why some metaphysical arguments are meaningless, and why some philosophical problems can be dissolved. (We'd have to be more specific about the Chalmers vs. Eliezer question before I could weigh in. For example, I find Chalmers' writing to be clearer, but Eliezer's choice of topics for investigation more important for the human species.)

Finally, I'll note that [Nick Bostrom](http://nickbostrom.com/) takes roughly the same approach to philosophy as Eliezer and I do, but Nick has a position at Oxford University, publishes in leading philosophy journals, and so on. On philosophical method, I recommend Nick's first professional paper, [Predictions from Philosophy](http://www.nickbostrom.com/old/predict.html) (1997). It sums up the motivation behind much of what Nick and Eliezer have done since then.